Do not handle .rmeta files as object

.github/.cspell/project-dictionary.txt

@@ -14,6 +14,7 @@ nextest
 notcovered
 profdata
 profraw
+rmeta
 rustfilt
 TESTNAME
 trybuild

CHANGELOG.md

@@ -10,6 +10,8 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
+- Fix "The file was not recognized as a valid object file" error with `--doc`/`--doctests` flag on WSL. ([#343](https://github.com/taiki-e/cargo-llvm-cov/pull/343))
+
 ## [0.6.2] - 2024-01-18
 
 - Support setting file name of `LLVM_PROFILE_FILE`. ([#340](https://github.com/taiki-e/cargo-llvm-cov/pull/340))

src/main.rs

@@ -709,7 +709,8 @@ fn object_files(cx: &Context) -> Result<Vec<OsString>> {
         let ext = f.extension().unwrap_or_default();
         // is_executable::is_executable doesn't work well on WSL.
         // https://github.com/taiki-e/cargo-llvm-cov/issues/316
-        if ext == "d" {
+        // https://github.com/taiki-e/cargo-llvm-cov/issues/342
+        if ext == "d" || ext == "rmeta" {
             return false;
         }
         if cx.ws.target_for_config.triple().contains("-windows")