Trunk fails to run if given a custom config file without path

[fiadliel]

Platform: MacOS
Version: Rev 32837ee of https://github.com/trunk-rs/trunk#328378ee

Trunk fails to run if given a custom config file without path.

$ trunk serve --config Trunk.test.toml
2024-08-02T06:04:50.980015Z  INFO 🚀 Starting trunk 0.21.0-alpha.4
2024-08-02T06:04:50.981228Z ERROR unable to canonicalize ''

This looks like an unfortunate interaction between PathBuf::parent and fs::canonicalize. It seems that given a bare filename, PathBuf::parent returns Some("") (empty string). However, fs::canonicalize does not consider this to represent the current working directory. Looking at the implementation, it is basically just a call to realpath in libc. And the POSIX specification for realpath says that passing an empty string should result in an error.

trunk does run with trunk serve --config $(pwd)/Trunk.test.toml or even trunk serve --config ./Trunk.test.toml.

References:

trunk/src/config/models/mod.rs

Line 122 in 328378e

let Some(cwd) = path.parent() else {

trunk/src/config/rt/core.rs

Line 26 in 328378e

.canonicalize()

https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.parent
https://doc.rust-lang.org/std/fs/fn.canonicalize.html
https://github.com/rust-lang/rust/blob/051478957371ee0084a7c0913941d2a8c4757bb9/library/std/src/sys/pal/unix/fs.rs#L1814
https://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html

[ctron]

Interesting. It also works if you have a relative directory path upfront, like I use for testing examples/foo/Trunk.toml. Or just the directory: foo (which defaults to Trunk.toml).