Fix pcb publish in board dir (#530)

* Fix `pcb publish` in board dir

* Add regression test

Author: akhilles

CHANGELOG.md

@@ -12,6 +12,10 @@ and this project adheres to Semantic Versioning (https://semver.org/spec/v2.0.0.
 
 - `load()` and `Module()` with relative paths can now cross package boundaries within a workspace, resolved through the dependency system.
 
+### Fixed
+
+- `pcb publish` now works when run from a board directory with a relative `.zen` path (e.g., `pcb publish DM0002.zen`).
+
 ### Changed
 
 - Resolve `Path()` and `File()` to stable relative paths for machine-independent build artifacts. 

crates/pcb/src/file_walker.rs

@@ -135,7 +135,10 @@ pub struct BoardTarget {
 pub fn resolve_board_target(path: &Path, action: &str) -> Result<BoardTarget> {
     require_zen_file(path)?;
     let file_provider = DefaultFileProvider::new();
-    let start_path = path.parent().unwrap_or(Path::new("."));
+    let start_path = path
+        .parent()
+        .filter(|p| !p.as_os_str().is_empty())
+        .unwrap_or(Path::new("."));
     let workspace = get_workspace_info(&file_provider, start_path)?;
 
     if !workspace.errors.is_empty() {

crates/pcb/tests/release.rs

@@ -345,3 +345,31 @@ fn test_publish_board_with_description() {
     let staging_dir = find_staging_dir(&sb, "DescBoard");
     assert_snapshot!("publish_with_description", sb.snapshot_dir(&staging_dir));
 }
+
+/// Test that `pcb publish` works when run from the board directory with a relative .zen path.
+/// Regression test: previously, `pcb publish DM0002.zen` from `boards/DM0002/` would fail
+/// with "No lockfile found" because workspace discovery broke on the empty parent path.
+#[test]
+fn test_publish_board_from_board_dir() {
+    let mut sb = Sandbox::new();
+    sb.cwd("src")
+        .write("pcb.toml", PCB_TOML)
+        .write("boards/pcb.toml", BOARD_PCB_TOML)
+        .write("boards/modules/LedModule.zen", LED_MODULE_ZEN)
+        .write("boards/TestBoard.zen", TEST_BOARD_ZEN)
+        .hash_globs(["*.kicad_mod", "**/diodeinc/stdlib/*.zen", "**/netlist.json"])
+        .ignore_globs(["layout/*", "**/vendor/**", "**/build/**"])
+        .init_git()
+        .commit("Initial commit");
+
+    // Build first to generate lockfile
+    sb.run("pcb", ["build", "boards/TestBoard.zen"])
+        .run()
+        .expect("build failed");
+
+    // Run publish from the board directory with a relative path
+    sb.cwd("src/boards")
+        .run("pcb", source_only_args("TestBoard.zen"))
+        .run()
+        .expect("publish from board dir with relative path should work");
+}