Failed to load coverage: The file was not recognized as a valid object file - in WSL

[robo9k]

This seems to be the same as #48 , however cargo clean did not fix it.

$ git clone --branch v0.15.0 https://github.com/robo9k/rust-magic.git

$ cargo +stable --version
cargo 1.72.1 (103a7ff2e 2023-08-15)

$ cargo +stable install cargo-llvm-cov --locked
cargo-llvm-cov 0.5.32

$ cargo +stable llvm-cov --lcov --output-path lcov.info
[..]
error: failed to generate report: process didn't exit successfully: `/home/robo9k/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-cov export -format=lcov -instr-profile=/mnt/c/Users/robo9k/projects/rust-magic/target/llvm-cov-target/rust-magic.profdata -object target/llvm-cov-target/debug/deps/magic-85046b25feefe3f1 -object target/llvm-cov-target/debug/deps/magic-85046b25feefe3f1.d -ignore-filename-regex '/rustc/([0-9a-f]+|[0-9]+\.[0-9]+\.[0-9]+)/|^/mnt/c/Users/robo9k/projects/rust\-magic(/.*)?/(tests|examples|benches)/|^/mnt/c/Users/robo9k/projects/rust\-magic/target/llvm\-cov\-target($|/)|^/home/robo9k/\.cargo/(registry|git)/|^/home/robo9k/\.rustup/toolchains($|/)'` (exit status: 1)
--- stderr
error: Failed to load coverage: 'target/llvm-cov-target/debug/deps/magic-85046b25feefe3f1.d': The file was not recognized as a valid object file
error: Could not load coverage information

Running cargo clean results in the same error. Running with CARGO_INCREMENTAL=0 cargo +stable llvm-cov --lcov --output-path lcov.info results in the same error.

The error occurs is in Ubuntu in WSL with a Windows folder (/mnt/c/Users/robo9k/projects/rust-magic).
When running this in a Linux directory (e.g. mktemp -d) instead, the command works:

    Finished report saved to lcov.info

I'm not sure if this is even something you can reasonably fix in cargo-llvm-cov. Just thought I'd file an issue so others can find the information/workaround. Feel free to close this right away.

[taiki-e]

Thanks for the report!

What is the permission of target/llvm-cov-target/debug/deps/magic-85046b25feefe3f1.d?

I guess that it is marked as executable for some reason.

[taiki-e]

Related: fitzgen/is_executable#12

[robo9k]

$ stat target/llvm-cov-target/debug/deps/magic-85046b25feefe3f1.d
  File: target/llvm-cov-target/debug/deps/magic-85046b25feefe3f1.d
  Size: 262             Blocks: 0          IO Block: 4096   regular file
Device: 48h/72d Inode: 8444249301454017  Links: 1
Access: (0777/-rwxrwxrwx)  Uid: ( 1000/  robo9k)   Gid: ( 1000/  robo9k)
Access: 2023-09-26 16:58:19.921217100 +0200
Modify: 2023-09-26 16:58:19.921217100 +0200
Change: 2023-09-26 16:58:19.921217100 +0200
 Birth: -

The Windows file is indeed executable (chmod 0777).