diff --git a/build.rs b/build.rs
index 84032c1..efb11ad 100644
--- a/build.rs
+++ b/build.rs
@@ -8,7 +8,7 @@ fn main() -> Result<(), Box<dyn Error>> {
     let target = std::env::var("TARGET")?;
 
     let output = std::env::var("OUT_DIR")?;
-    ::std::fs::write(format!("{}/target", output), target.as_bytes())?;
+    ::std::fs::write(format!("{output}/target"), target.as_bytes())?;
 
     println!("cargo:rerun-if-env-changed=DOCS_RS");
     if std::env::var_os("DOCS_RS").as_deref() == Some(std::ffi::OsStr::new("1")) {
diff --git a/src/build.rs b/src/build.rs
index 6df0e62..4d8c95d 100644
--- a/src/build.rs
+++ b/src/build.rs
@@ -1,6 +1,6 @@
 use crate::cmd::{Command, MountKind, Runnable, SandboxBuilder};
 use crate::prepare::Prepare;
-use crate::{Crate, Toolchain, Workspace};
+use crate::{Crate, PrepareError, Toolchain, Workspace};
 use std::path::PathBuf;
 use std::vec::Vec;
 
@@ -194,7 +194,13 @@ impl BuildDirectory {
         }
 
         let mut prepare = Prepare::new(&self.workspace, toolchain, krate, &source_dir, patches);
-        prepare.prepare()?;
+        prepare.prepare().map_err(|err| {
+            if err.downcast_ref::<PrepareError>().is_none() {
+                err.context(PrepareError::Uncategorized)
+            } else {
+                err
+            }
+        })?;
 
         std::fs::create_dir_all(self.target_dir())?;
         let res = f(&Build {
diff --git a/src/cmd/mod.rs b/src/cmd/mod.rs
index 922592a..5077033 100644
--- a/src/cmd/mod.rs
+++ b/src/cmd/mod.rs
@@ -501,14 +501,14 @@ impl<'w, 'pl> Command<'w, 'pl> {
                 cmd.env(k, v);
             }
 
-            let cmdstr = format!("{:?}", cmd);
+            let cmdstr = format!("{cmd:?}");
 
             if let Some(ref cd) = self.cd {
                 cmd.current_dir(cd);
             }
 
             if self.log_command {
-                info!("running `{}`", cmdstr);
+                info!("running `{cmdstr}`");
             }
 
             let out = RUNTIME
@@ -521,7 +521,7 @@ impl<'w, 'pl> Command<'w, 'pl> {
                     self.log_output,
                 ))
                 .map_err(|e| {
-                    error!("error running command: {}", e);
+                    error!("error running command: {e}");
                     e
                 })?;
 
diff --git a/src/cmd/sandbox.rs b/src/cmd/sandbox.rs
index e553ead..3a3954b 100644
--- a/src/cmd/sandbox.rs
+++ b/src/cmd/sandbox.rs
@@ -29,7 +29,7 @@ impl SandboxImage {
     /// error will be returned instead.
     pub fn remote(name: &str) -> Result<Self, CommandError> {
         let mut image = SandboxImage { name: name.into() };
-        info!("pulling image {} from Docker Hub", name);
+        info!("pulling image {name} from Docker Hub");
         Command::new_workspaceless("docker")
             .args(&["pull", name])
             .run()
@@ -219,7 +219,7 @@ impl SandboxBuilder {
     }
 
     pub(super) fn user(mut self, user: u32, group: u32) -> Self {
-        self.user = Some(format!("{}:{}", user, group));
+        self.user = Some(format!("{user}:{group}"));
         self
     }
 
@@ -242,7 +242,7 @@ impl SandboxBuilder {
 
         for (var, value) in &self.env {
             args.push("-e".into());
-            args.push(format! {"{}={}", var, value})
+            args.push(format! {"{var}={value}"})
         }
 
         if let Some(workdir) = self.workdir {
@@ -308,10 +308,10 @@ impl SandboxBuilder {
         scopeguard::defer! {{
             if let Err(err) = container.delete() {
                 error!("failed to delete container {}", container.id);
-                error!("caused by: {}", err);
+                error!("caused by: {err}");
                 let mut err: &dyn Error = &err;
                 while let Some(cause) = err.source() {
-                    error!("caused by: {}", cause);
+                    error!("caused by: {cause}");
                     err = cause;
                 }
             }
diff --git a/src/crates/registry.rs b/src/crates/registry.rs
index 26344fb..fd89993 100644
--- a/src/crates/registry.rs
+++ b/src/crates/registry.rs
@@ -122,7 +122,7 @@ impl RegistryCrate {
                     git2::build::RepoBuilder::new()
                         .fetch_options(fo)
                         .clone(url, &index_path)
-                        .with_context(|| format!("unable to update_index at {}", url))?;
+                        .with_context(|| format!("unable to update_index at {url}"))?;
                     info!("cloned registry index");
                 }
                 let config = std::fs::read_to_string(index_path.join("config.json"))?;
diff --git a/src/inside_docker.rs b/src/inside_docker.rs
index af3c513..ec3cb4c 100644
--- a/src/inside_docker.rs
+++ b/src/inside_docker.rs
@@ -62,7 +62,7 @@ pub(crate) fn probe_container_id(workspace: &Workspace) -> anyhow::Result<Option
         .log_command(false)
         .run_capture()?;
     for id in out.stdout_lines() {
-        info!("probing container id {}", id);
+        info!("probing container id {id}");
 
         let res = Command::new(workspace, "docker")
             .args(&["exec", id, "cat", probe_path_str])
@@ -71,7 +71,7 @@ pub(crate) fn probe_container_id(workspace: &Workspace) -> anyhow::Result<Option
             .run_capture();
         if let Ok([probed]) = res.as_ref().map(|out| out.stdout_lines()) {
             if *probed == probe_content {
-                info!("probe successful, this is container ID {}", id);
+                info!("probe successful, this is container ID {id}");
                 return Ok(Some(id.clone()));
             }
         }
diff --git a/src/prepare.rs b/src/prepare.rs
index a0d4110..01e85d5 100644
--- a/src/prepare.rs
+++ b/src/prepare.rs
@@ -268,7 +268,7 @@ impl<'a> TomlTweaker<'a> {
         // Eliminate parent workspaces
         if let Some(&mut Value::Table(ref mut package)) = self.table.get_mut("package") {
             if package.remove("workspace").is_some() {
-                info!("removed parent workspace from {}", krate);
+                info!("removed parent workspace from {krate}");
             }
         }
     }
@@ -295,7 +295,7 @@ impl<'a> TomlTweaker<'a> {
 
         // Strip the 'publish-lockfile' key from [package]
         if has_publish_lockfile {
-            info!("disabled cargo feature 'publish-lockfile' from {}", krate);
+            info!("disabled cargo feature 'publish-lockfile' from {krate}");
             if let Some(&mut Value::Table(ref mut package)) = self.table.get_mut("package") {
                 package.remove("publish-lockfile");
             }
@@ -303,7 +303,7 @@ impl<'a> TomlTweaker<'a> {
 
         // Strip the 'default-run' key from [package]
         if has_default_run {
-            info!("disabled cargo feature 'default-run' from {}", krate);
+            info!("disabled cargo feature 'default-run' from {krate}");
             if let Some(&mut Value::Table(ref mut package)) = self.table.get_mut("package") {
                 package.remove("default-run");
             }
@@ -390,6 +390,10 @@ pub enum PrepareError {
     /// Some of the dependencies do not exist anymore.
     #[error("the crate depends on missing dependencies: \n\n{0}")]
     MissingDependencies(String),
+    /// Uncategorized error
+    #[doc(hidden)]
+    #[error("uncategorized prepare error")]
+    Uncategorized,
 }
 
 #[cfg(test)]
diff --git a/src/toolchain.rs b/src/toolchain.rs
index 2fb04c3..572d385 100644
--- a/src/toolchain.rs
+++ b/src/toolchain.rs
@@ -407,8 +407,7 @@ impl Toolchain {
                 .collect()),
             Err(_) if not_installed => Err(ToolchainError::NotInstalled.into()),
             Err(err) => Err(anyhow!(err).context(format!(
-                "failed to read the list of installed {}s for {} with rustup",
-                thing, name
+                "failed to read the list of installed {thing}s for {name} with rustup"
             ))),
         }
     }
@@ -419,7 +418,7 @@ impl Toolchain {
         Command::new(workspace, &RUSTUP)
             .args(&["toolchain", "uninstall", &name])
             .run()
-            .with_context(|| format!("unable to uninstall toolchain {} via rustup", name))?;
+            .with_context(|| format!("unable to uninstall toolchain {name} via rustup"))?;
         Ok(())
     }
 
diff --git a/src/tools/rustup.rs b/src/tools/rustup.rs
index 5aa132b..ec95d41 100644
--- a/src/tools/rustup.rs
+++ b/src/tools/rustup.rs
@@ -49,7 +49,7 @@ impl Tool for Rustup {
             .error_for_status()?;
 
         let tempdir = tempdir()?;
-        let installer = &tempdir.path().join(format!("rustup-init{}", EXE_SUFFIX));
+        let installer = &tempdir.path().join(format!("rustup-init{EXE_SUFFIX}"));
         {
             let mut file = File::create(installer)?;
             io::copy(&mut resp, &mut file)?;
@@ -81,7 +81,7 @@ impl Tool for Rustup {
         Command::new(workspace, &RUSTUP)
             .args(&["update", MAIN_TOOLCHAIN_NAME])
             .run()
-            .with_context(|| format!("failed to update main toolchain {}", MAIN_TOOLCHAIN_NAME))?;
+            .with_context(|| format!("failed to update main toolchain {MAIN_TOOLCHAIN_NAME}"))?;
         Ok(())
     }
 }
diff --git a/src/utils.rs b/src/utils.rs
index 55387e6..77ababb 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -35,7 +35,7 @@ pub(crate) fn file_lock<T>(
     let mut message_displayed = false;
     while let Err(err) = file.try_lock_exclusive() {
         if !message_displayed && err.kind() == fs2::lock_contended_error().kind() {
-            warn!("blocking on other processes finishing to {}", msg);
+            warn!("blocking on other processes finishing to {msg}");
             message_displayed = true;
         }
         file.lock_exclusive()?;
diff --git a/tests/buildtest/crates/invalid-cargotoml-conflicting-links/Cargo.lock b/tests/buildtest/crates/invalid-cargotoml-conflicting-links/Cargo.lock
new file mode 100644
index 0000000..fcd0b44
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-conflicting-links/Cargo.lock
@@ -0,0 +1,98 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "cc"
+version = "1.2.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04da6a0d40b948dfc4fa8f5bbf402b0fc1a64a28dbf7d12ffd683550f2c1b63a"
+dependencies = [
+ "shlex",
+]
+
+[[package]]
+name = "invalid-cargotoml-conflicting-links"
+version = "0.1.0"
+dependencies = [
+ "ring 0.13.5",
+ "ring 0.14.6",
+]
+
+[[package]]
+name = "lazy_static"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+
+[[package]]
+name = "libc"
+version = "0.2.172"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d750af042f7ef4f724306de029d18836c26c1765a54a6a3f094cbd23a7267ffa"
+
+[[package]]
+name = "ring"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c4db68a2e35f3497146b7e4563df7d4773a2433230c5e4b448328e31740458a"
+dependencies = [
+ "cc",
+ "lazy_static",
+ "libc",
+ "untrusted",
+]
+
+[[package]]
+name = "ring"
+version = "0.14.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "426bc186e3e95cac1e4a4be125a4aca7e84c2d616ffc02244eef36e2a60a093c"
+dependencies = [
+ "cc",
+ "lazy_static",
+ "libc",
+ "spin",
+ "untrusted",
+ "winapi",
+]
+
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
+
+[[package]]
+name = "untrusted"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55cd1f4b4e96b46aeb8d4855db4a7a9bd96eeeb5c6a1ab54593328761642ce2f"
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
diff --git a/tests/buildtest/crates/invalid-cargotoml-conflicting-links/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-conflicting-links/Cargo.toml
new file mode 100644
index 0000000..d397cb2
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-conflicting-links/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "invalid-cargotoml-conflicting-links"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+ring_13 = { version = "=0.13.5", package = "ring" }
+ring_14 = { version = "=0.14.6", package = "ring" }
+
+
+[replace]
+"ring:0.13.5" = { git = "https://github.com/briansmith/ring.git", rev = "704e4216a397bd830479bcd6d7dd67fc62cdbe67" }
+"ring:0.14.6" = { git = "https://github.com/briansmith/ring.git", rev = "ef85df478152aa3fe06c811309379efa08f8a529" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-conflicting-links/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-conflicting-links/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-conflicting-links/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-content-deps/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-content-deps/Cargo.toml
new file mode 100644
index 0000000..e7ca4e7
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-content-deps/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "invalid-cargotoml-content-deps"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+parity-db = "=0.2.3"
+# invalid package name in invalid-cargotoml-content is too invalid
+# invalid-cargotoml-content = { git = "https://github.com/rust-lang/rustwide.git", rev = "ee102383cbe40aafdfce7bf04a120226c16a8983" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-content-deps/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-content-deps/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-content-deps/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/Cargo.lock b/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/Cargo.lock
new file mode 100644
index 0000000..1861b69
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/Cargo.lock
@@ -0,0 +1,25 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "invalid-cargotoml-content-type-in-deps"
+version = "0.1.0"
+dependencies = [
+ "libressl-pnacl-sys",
+]
+
+[[package]]
+name = "libressl-pnacl-sys"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbbd33b70b69d25b726e2e747833e22c7ebd98cc46da2b368f45b36b4d026395"
+dependencies = [
+ "pnacl-build-helper",
+]
+
+[[package]]
+name = "pnacl-build-helper"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eb74016978b58b71690dc3bb9a4890bd41dac2d4c6835249edf71a698dbc2db"
diff --git a/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/Cargo.toml
new file mode 100644
index 0000000..abf3e74
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "invalid-cargotoml-content-type-in-deps"
+version = "0.1.0"
+authors = []
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+libressl-pnacl-sys = "=2.1.0"
diff --git a/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-content-type-in-deps/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-cyclic-feature/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-cyclic-feature/Cargo.toml
new file mode 100644
index 0000000..915e692
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-cyclic-feature/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "invalid-cargotoml-cyclic-feature"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[features]
+cyclic = ["cyclic"]
diff --git a/tests/buildtest/crates/invalid-cargotoml-cyclic-feature/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-cyclic-feature/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-cyclic-feature/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-cyclic-package/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-cyclic-package/Cargo.toml
new file mode 100644
index 0000000..b5a0a5d
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-cyclic-package/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "invalid-cargotoml-cyclic-package"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+invalid-cargotoml-cyclic-package = { path = "./" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-cyclic-package/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-cyclic-package/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-cyclic-package/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-override/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-missing-override/Cargo.toml
new file mode 100644
index 0000000..f44d7f5
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-override/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "invalid-cargotoml-missing-override"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+build-rs = "=0.1.2"
+
+[replace]
+"build-rs:0.1.2" = { git = "https://github.com/rust-lang/rustwide.git", rev = "07784be00b68cfd6bf80006c8d8669a7d6374ec2" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-override/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-missing-override/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-override/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-patch/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-missing-patch/Cargo.toml
new file mode 100644
index 0000000..b7fc03d
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-patch/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "invalid-cargotoml-missing-patch"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+build-rs = "=0.1.2"
+
+[patch.crates-io]
+build-rs = { git = "https://github.com/rust-lang/rustwide.git", rev = "07784be00b68cfd6bf80006c8d8669a7d6374ec2" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-patch/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-missing-patch/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-patch/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/.cargo/config.toml b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/.cargo/config.toml
new file mode 100644
index 0000000..01e9dc1
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/.cargo/config.toml
@@ -0,0 +1,2 @@
+[registries]
+will-be-removed = { index = "https://github.com/rust-lang/crates.io-index" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/Cargo.lock b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/Cargo.lock
new file mode 100644
index 0000000..0af6668
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "invalid-cargotoml-missing-registry-config"
+version = "0.1.0"
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/Cargo.toml
new file mode 100644
index 0000000..40efe3b
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "invalid-cargotoml-missing-registry-config"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+build-rs = { version = "*", registry = "will-be-removed" }
diff --git a/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-missing-registry-config/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-cargotoml-syntax-deps/Cargo.toml b/tests/buildtest/crates/invalid-cargotoml-syntax-deps/Cargo.toml
new file mode 100644
index 0000000..7f319f6
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-syntax-deps/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "invalid-cargotoml-syntax-deps"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+url = "=0.5.9"
diff --git a/tests/buildtest/crates/invalid-cargotoml-syntax-deps/src/main.rs b/tests/buildtest/crates/invalid-cargotoml-syntax-deps/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-cargotoml-syntax-deps/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/invalid-lockfile-syntax/Cargo.lock b/tests/buildtest/crates/invalid-lockfile-syntax/Cargo.lock
new file mode 100644
index 0000000..093a780
--- /dev/null
+++ b/tests/buildtest/crates/invalid-lockfile-syntax/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "invalid-lockfile-syntax
+version = "0.1.0"
diff --git a/tests/buildtest/crates/invalid-lockfile-syntax/Cargo.toml b/tests/buildtest/crates/invalid-lockfile-syntax/Cargo.toml
new file mode 100644
index 0000000..45ef771
--- /dev/null
+++ b/tests/buildtest/crates/invalid-lockfile-syntax/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "invalid-lockfile-syntax"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/tests/buildtest/crates/invalid-lockfile-syntax/src/main.rs b/tests/buildtest/crates/invalid-lockfile-syntax/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/invalid-lockfile-syntax/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/lockfile-collision/Cargo.toml b/tests/buildtest/crates/lockfile-collision/Cargo.toml
new file mode 100644
index 0000000..db22620
--- /dev/null
+++ b/tests/buildtest/crates/lockfile-collision/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "lockfile-collision"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+lockfile-collision = { path = "./crates/lockfile-collision" }
diff --git a/tests/buildtest/crates/lockfile-collision/crates/lockfile-collision/Cargo.toml b/tests/buildtest/crates/lockfile-collision/crates/lockfile-collision/Cargo.toml
new file mode 100644
index 0000000..34e77d1
--- /dev/null
+++ b/tests/buildtest/crates/lockfile-collision/crates/lockfile-collision/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "lockfile-collision"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/tests/buildtest/crates/lockfile-collision/crates/lockfile-collision/src/lib.rs b/tests/buildtest/crates/lockfile-collision/crates/lockfile-collision/src/lib.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/lockfile-collision/crates/lockfile-collision/src/lib.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/lockfile-collision/src/main.rs b/tests/buildtest/crates/lockfile-collision/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/lockfile-collision/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/missing-deps-git/Cargo.toml b/tests/buildtest/crates/missing-deps-git/Cargo.toml
index 7e65c56..ceba8ea 100644
--- a/tests/buildtest/crates/missing-deps-git/Cargo.toml
+++ b/tests/buildtest/crates/missing-deps-git/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "missing-deps"
+name = "missing-deps-git"
 version = "0.1.0"
 authors = ["Pietro Albini <pietro@pietroalbini.org>"]
 edition = "2018"
diff --git a/tests/buildtest/crates/missing-deps-registry-version/Cargo.lock b/tests/buildtest/crates/missing-deps-registry-version/Cargo.lock
new file mode 100644
index 0000000..81155a1
--- /dev/null
+++ b/tests/buildtest/crates/missing-deps-registry-version/Cargo.lock
@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "empty-library"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09f2aa7b9820e9739aa1443425ad1f7deb9e7686d276d867e9c4752189b3130c"
+
+[[package]]
+name = "missing-deps-registry-version"
+version = "0.1.0"
+dependencies = [
+ "empty-library",
+]
diff --git a/tests/buildtest/crates/missing-deps-registry-version/Cargo.toml b/tests/buildtest/crates/missing-deps-registry-version/Cargo.toml
new file mode 100644
index 0000000..40b69be
--- /dev/null
+++ b/tests/buildtest/crates/missing-deps-registry-version/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "missing-deps-registry-version"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+empty-library = "=0.5.0"
diff --git a/tests/buildtest/crates/missing-deps-registry-version/src/main.rs b/tests/buildtest/crates/missing-deps-registry-version/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/missing-deps-registry-version/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/crates/missing-deps-typo/Cargo.toml b/tests/buildtest/crates/missing-deps-typo/Cargo.toml
new file mode 100644
index 0000000..afc3e9d
--- /dev/null
+++ b/tests/buildtest/crates/missing-deps-typo/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "missing-deps-typo"
+version = "0.1.0"
+authors = ["Pietro Albini <pietro@pietroalbini.org>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+# it's build-rs (dash vs. underscore)
+build_rs = "*"
diff --git a/tests/buildtest/crates/missing-deps-typo/src/main.rs b/tests/buildtest/crates/missing-deps-typo/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/tests/buildtest/crates/missing-deps-typo/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/tests/buildtest/mod.rs b/tests/buildtest/mod.rs
index 594df51..be4f824 100644
--- a/tests/buildtest/mod.rs
+++ b/tests/buildtest/mod.rs
@@ -5,6 +5,51 @@ use rustwide::cmd::{ProcessLinesActions, SandboxBuilder};
 mod runner;
 mod inside_docker;
 
+#[test]
+fn buildtest_crate_name_matches_folder_name() {
+    for result in std::fs::read_dir(concat!(
+        env!("CARGO_MANIFEST_DIR"),
+        "/tests/buildtest/crates"
+    ))
+    .unwrap()
+    {
+        let dir_entry = result.unwrap();
+        if dir_entry.file_type().unwrap().is_dir() {
+            let dir_name = dir_entry.file_name();
+
+            if [
+                "cargo-workspace".as_ref(),
+                "invalid-cargotoml-syntax".as_ref(),
+            ]
+            .contains(&dir_name.as_os_str())
+            {
+                continue;
+            }
+
+            let expected_crate_name = if dir_name != "invalid-cargotoml-content" {
+                dir_name.clone()
+            } else {
+                "!".into()
+            };
+
+            let cargo_toml_path = dir_entry.path().join("Cargo.toml");
+
+            if !cargo_toml_path.exists() {
+                continue;
+            }
+
+            let cargo_toml_content = std::fs::read_to_string(&cargo_toml_path).unwrap();
+
+            assert!(
+                cargo_toml_content.contains(&format!("name = {expected_crate_name:?}")),
+                "directory {:?} does not contain a crate with the expected name {:?}",
+                dir_name,
+                expected_crate_name
+            )
+        }
+    }
+}
+
 #[test]
 fn test_hello_world() {
     runner::run("hello-world", |run| {
@@ -199,7 +244,7 @@ test_prepare_error_stderr!(
     test_missing_deps_git,
     "missing-deps-git",
     MissingDependencies,
-    "failed to get `not-a-git-repo` as a dependency of package `missing-deps v0.1.0"
+    "failed to get `not-a-git-repo` as a dependency of package `missing-deps-git v0.1.0"
 );
 
 test_prepare_error_stderr!(
@@ -215,3 +260,93 @@ test_prepare_error_stderr!(
     MissingDependencies,
     "error: no matching package named `macro` found"
 );
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_content_deps,
+    "invalid-cargotoml-content-deps",
+    BrokenDependencies,
+    "failed to parse the version requirement `0.11\t` for dependency `parking_lot`"
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_syntax_deps,
+    "invalid-cargotoml-syntax-deps",
+    BrokenDependencies,
+    "error: invalid table header"
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_lockfile_syntax,
+    "invalid-lockfile-syntax",
+    InvalidCargoLock,
+    "error: failed to parse lock file at"
+);
+
+test_prepare_uncategorized_err!(
+    test_missing_deps_typo,
+    "missing-deps-typo",
+    MissingDependencies,
+    "error: no matching package found"
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_cyclic_feature,
+    "invalid-cargotoml-cyclic-feature",
+    BrokenDependencies,
+    "error: cyclic feature dependency: feature"
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_cyclic_package,
+    "invalid-cargotoml-cyclic-package",
+    BrokenDependencies,
+    "error: cyclic package dependency: package"
+);
+
+test_prepare_error!(
+    test_invalid_cargotoml_missing_registry_config,
+    "invalid-cargotoml-missing-registry-config",
+    InvalidCargoTomlSyntax
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_missing_override,
+    "invalid-cargotoml-missing-override",
+    MissingDependencies,
+    "no matching package for override `https://github.com/rust-lang/crates.io-index#build-rs@0.1.2` found"
+);
+
+test_prepare_uncategorized_err!(
+    test_missing_deps_registry_version,
+    "missing-deps-registry-version",
+    MissingDependencies,
+    "error: failed to select a version for the requirement `empty-library = \"=0.5.0\"`"
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_content_type_in_deps,
+    "invalid-cargotoml-content-type-in-deps",
+    BrokenDependencies,
+    "error: invalid type: map, expected a string"
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_conflicting_links,
+    "invalid-cargotoml-conflicting-links",
+    InvalidCargoLock,
+    "error: Attempting to resolve a dependency with more than one crate with links=ring-asm"
+);
+
+test_prepare_uncategorized_err!(
+    test_lockfile_collision,
+    "lockfile-collision",
+    BrokenDependencies,
+    "error: package collision in the lockfile: packages lockfile-collision v0.1.0 "
+);
+
+test_prepare_uncategorized_err!(
+    test_invalid_cargotoml_missing_patch,
+    "invalid-cargotoml-missing-patch",
+    MissingDependencies,
+    "The patch location `https://github.com/rust-lang/rustwide.git?rev=07784be00b68cfd6bf80006c8d8669a7d6374ec2` does not appear to contain any packages matching the name `build-rs`"
+);
diff --git a/tests/buildtest/runner.rs b/tests/buildtest/runner.rs
index a849d16..73b3c48 100644
--- a/tests/buildtest/runner.rs
+++ b/tests/buildtest/runner.rs
@@ -72,12 +72,23 @@ macro_rules! test_prepare_error {
                     rustwide::cmd::SandboxBuilder::new().enable_networking(false),
                     |_| Ok(()),
                 );
-                if let Some(rustwide::PrepareError::$expected) =
-                    res.err().and_then(|err| err.downcast().ok())
-                {
-                    // Everything is OK!
-                } else {
-                    panic!("didn't get the error {}", stringify!($expected));
+                match res.err().and_then(|err| err.downcast().ok()) {
+                    Some(rustwide::PrepareError::$expected) => {
+                        // Everything is OK!
+                    }
+                    Some(other) => {
+                        panic!(
+                            "expected PrepareError::{} error, got {:?} instead",
+                            stringify!($expected),
+                            other
+                        );
+                    }
+                    None => {
+                        panic!(
+                            "expected PrepareError::{} error, but did get None instead",
+                            stringify!($expected)
+                        );
+                    }
                 }
                 Ok(())
             });
@@ -85,6 +96,8 @@ macro_rules! test_prepare_error {
     };
 }
 
+pub(crate) use test_prepare_error;
+
 macro_rules! test_prepare_error_stderr {
     ($name:ident, $krate:expr, $expected:ident, $expected_output:expr) => {
         #[test]
@@ -94,15 +107,32 @@ macro_rules! test_prepare_error_stderr {
                     rustwide::cmd::SandboxBuilder::new().enable_networking(false),
                     |_| Ok(()),
                 );
-                if let Some(rustwide::PrepareError::$expected(output)) =
-                    res.err().and_then(|err| err.downcast().ok())
-                {
-                    assert!(output.contains($expected_output), "output: {:?}", output);
-                } else {
-                    panic!("didn't get the error {}", stringify!($expected));
+                match res.err().and_then(|err| err.downcast().ok()) {
+                    Some(rustwide::PrepareError::$expected(output)) => {
+                        assert!(output.contains($expected_output), "output: {:?}", output);
+                    }
+                    Some(other) => {
+                        panic!(
+                            "expected PrepareError::{} error, got {:?} instead",
+                            stringify!($expected),
+                            other
+                        );
+                    }
+                    None => {
+                        panic!(
+                            "expected PrepareError::{} error, but did get None instead",
+                            stringify!($expected)
+                        );
+                    }
                 }
                 Ok(())
             });
         }
     };
 }
+
+macro_rules! test_prepare_uncategorized_err {
+    ($name:ident, $krate:expr, $expected:ident $(,$expected_output:expr)?) => {
+        $crate::buildtest::runner::test_prepare_error!($name, $krate, Uncategorized);
+    };
+}