fix(mktemp): add wasi platform support for temporary directory handling

- Add conditional compilation for WASI target to avoid panics from `std::env::temp_dir()`
- Implement fallback logic in `Options` to read TMPDIR environment variable directly on WASI
- Update `get_tmpdir_env_or_default()` with WASI-specific handling for temp directory resolution
- Add `#[cfg_attr]` annotations to skip host path-dependent tests on WASI sandbox environment
- Ignore 14 tests that require host filesystem access when running under wasi_runner
- Ignore directory permission test on WASI due to lack of `chmod` support and mode parameter limitations

Author: eduardomourar

.github/workflows/wasi.yml

@@ -71,7 +71,7 @@ jobs:
           test_base32:: test_base64:: test_basenc:: test_basename:: \
           test_comm:: test_cut:: test_dirname:: test_echo:: \
           test_expand:: test_factor:: test_false:: test_fold:: \
-          test_head:: test_link:: test_ln:: test_nl:: test_numfmt:: \
+          test_head:: test_link:: test_ln:: test_mktemp:: test_nl:: test_numfmt:: \
           test_od:: test_paste:: test_printf:: test_shuf:: test_sum:: \
           test_tee:: test_tr:: test_true:: test_truncate:: \
           test_unexpand:: test_unlink:: test_wc:: test_yes::

src/uu/mktemp/src/mktemp.rs

@@ -143,7 +143,13 @@ impl Options {
                 } else if matches.get_flag(OPT_T) || matches.contains_id(OPT_TMPDIR) {
                     // If --tmpdir is given without an argument, or -t is given
                     // export in TMPDIR
-                    Some(env::temp_dir())
+                    #[cfg(target_os = "wasi")]
+                    // WASI's `std::env::temp_dir()` unconditionally panics
+                    let default_tmp_dir = env::var_os(TMPDIR_ENV_VAR)
+                        .map_or_else(|| PathBuf::from(FALLBACK_TMPDIR), PathBuf::from);
+                    #[cfg(not(target_os = "wasi"))]
+                    let default_tmp_dir = env::temp_dir();
+                    Some(default_tmp_dir)
                 } else {
                     None
                 };
@@ -629,6 +635,13 @@ fn exec(dir: &Path, prefix: &str, rand: usize, suffix: &str, make_dir: bool) ->
 fn get_tmpdir_env_or_default() -> PathBuf {
     match env::var_os(TMPDIR_ENV_VAR) {
         Some(val) if val.is_empty() => PathBuf::from(FALLBACK_TMPDIR),
+        // WASI's `std::env::temp_dir()` unconditionally panics,
+        // so read `TMPDIR` directly.
+        #[cfg(target_os = "wasi")]
+        Some(val) => PathBuf::from(val),
+        #[cfg(target_os = "wasi")]
+        None => PathBuf::from(FALLBACK_TMPDIR),
+        #[cfg(not(target_os = "wasi"))]
         _ => env::temp_dir(),
     }
 }

tests/by-util/test_install.rs

@@ -789,7 +789,15 @@ fn test_install_and_strip() {
     let scene = TestScenario::new(util_name!());
     let at = &scene.fixtures;
 
-    at.write("strip", STRIP_PROGRAM);
+    // Write the strip script and sync to disk to avoid ETXTBSY race on some
+    // platforms (observed on ARM64 Linux CI runners).
+    let strip_path = at.plus("strip");
+    {
+        use std::io::Write;
+        let mut f = fs::File::create(&strip_path).unwrap();
+        f.write_all(STRIP_PROGRAM.as_bytes()).unwrap();
+        f.sync_all().unwrap();
+    }
     at.set_mode("strip", 0o755);
     at.write("source", "file contents");
     let path = format!(
@@ -830,7 +838,15 @@ fn test_install_and_strip_with_program() {
     let scene = TestScenario::new(util_name!());
     let at = &scene.fixtures;
 
-    at.write("strip-program", STRIP_PROGRAM);
+    // Write the strip script and sync to disk to avoid ETXTBSY race on some
+    // platforms (observed on ARM64 Linux CI runners).
+    let strip_path = at.plus("strip-program");
+    {
+        use std::io::Write;
+        let mut f = fs::File::create(&strip_path).unwrap();
+        f.write_all(STRIP_PROGRAM.as_bytes()).unwrap();
+        f.sync_all().unwrap();
+    }
     at.set_mode("strip-program", 0o755);
     at.write("source", "file contents");
 

tests/by-util/test_mktemp.rs

@@ -118,6 +118,7 @@ fn test_mktemp_mktemp() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_mktemp_mktemp_t() {
     let scene = TestScenario::new(util_name!());
 
@@ -399,6 +400,7 @@ fn test_mktemp_suffix() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_mktemp_tmpdir() {
     let scene = TestScenario::new(util_name!());
     let dir = tempdir().unwrap();
@@ -462,6 +464,7 @@ fn test_mktemp_tmpdir() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_mktemp_empty_tmpdir() {
     let scene = TestScenario::new(util_name!());
     let pathname = scene.fixtures.as_string();
@@ -482,6 +485,7 @@ fn test_mktemp_empty_tmpdir() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_mktemp_tmpdir_one_arg() {
     let scene = TestScenario::new(util_name!());
 
@@ -495,6 +499,7 @@ fn test_mktemp_tmpdir_one_arg() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_mktemp_directory_tmpdir() {
     let scene = TestScenario::new(util_name!());
 
@@ -599,6 +604,11 @@ fn test_respect_template_directory() {
 
 #[cfg(unix)]
 #[test]
+#[cfg_attr(
+    wasi_runner,
+    ignore = "WASI: path_create_directory has no mode parameter and chmod returns ENOSYS, \
+              so directories can't be created with restricted permissions"
+)]
 fn test_directory_permissions() {
     let (at, mut ucmd) = at_and_ucmd!();
     let result = ucmd.args(&["-d", "XXX"]).succeeds();
@@ -869,6 +879,7 @@ fn test_nonexistent_tmpdir_env_var() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_empty_tmpdir_env_var() {
     #[cfg(not(any(windows, target_os = "android")))]
     {
@@ -967,11 +978,13 @@ fn test_nonexistent_dir_prefix() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_default_missing_value() {
     new_ucmd!().arg("-d").arg("--tmpdir").succeeds();
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_default_issue_4821_t_tmpdir() {
     let scene = TestScenario::new(util_name!());
     let pathname = scene.fixtures.as_string();
@@ -987,6 +1000,7 @@ fn test_default_issue_4821_t_tmpdir() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_default_issue_4821_t_tmpdir_p() {
     let scene = TestScenario::new(util_name!());
     let pathname = scene.fixtures.as_string();
@@ -1003,6 +1017,7 @@ fn test_default_issue_4821_t_tmpdir_p() {
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_t_ensure_tmpdir_has_higher_priority_than_p() {
     let scene = TestScenario::new(util_name!());
     let pathname = scene.fixtures.as_string();
@@ -1099,7 +1114,8 @@ fn test_missing_short_tmpdir_flag() {
 }
 
 #[test]
-#[cfg(target_os = "linux")]
+#[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: wasmtime rejects non-UTF-8 arguments")]
 fn test_non_utf8_template() {
     use std::ffi::OsStr;
     use std::os::unix::ffi::OsStrExt;
@@ -1114,6 +1130,7 @@ fn test_non_utf8_template() {
 
 #[test]
 #[cfg(target_os = "linux")]
+#[cfg_attr(wasi_runner, ignore = "WASI: wasmtime rejects non-UTF-8 arguments")]
 fn test_non_utf8_tmpdir_path() {
     use std::os::unix::ffi::OsStrExt;
     let (at, mut ucmd) = at_and_ucmd!();
@@ -1128,6 +1145,7 @@ fn test_non_utf8_tmpdir_path() {
 
 #[test]
 #[cfg(target_os = "linux")]
+#[cfg_attr(wasi_runner, ignore = "WASI: wasmtime rejects non-UTF-8 arguments")]
 fn test_non_utf8_tmpdir_long_option() {
     use std::os::unix::ffi::OsStrExt;
     let (at, mut ucmd) = at_and_ucmd!();
@@ -1146,7 +1164,8 @@ fn test_non_utf8_tmpdir_long_option() {
 }
 
 #[test]
-#[cfg(target_os = "linux")]
+#[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: wasmtime rejects non-UTF-8 arguments")]
 fn test_invalid_utf8_suffix() {
     use std::os::unix::ffi::OsStrExt;
     let (at, mut ucmd) = at_and_ucmd!();
@@ -1167,6 +1186,7 @@ fn test_invalid_utf8_suffix() {
 
 #[test]
 #[cfg(target_os = "linux")]
+#[cfg_attr(wasi_runner, ignore = "WASI: wasmtime rejects non-UTF-8 arguments")]
 fn test_non_utf8_tmpdir_directory_creation() {
     use std::os::unix::ffi::OsStrExt;
     let (at, mut ucmd) = at_and_ucmd!();
@@ -1183,6 +1203,7 @@ fn test_non_utf8_tmpdir_directory_creation() {
 
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_mktemp_hidden_file_single_dot() {
     let scene = TestScenario::new(util_name!());
     let dir = tempdir().unwrap();