1.13.0/1.13.1: test `write_dist_info_uses_license_file_sources` fails

[dvzrv]

Bug Description

Hi! 👋

When trying to upgrade the package on Arch Linux to 1.13.0 or 1.13.1 I ran into the following failing test:

failures:

---- module_writer::mock_writer::write_dist_info_uses_license_file_sources stdout ----

thread 'module_writer::mock_writer::write_dist_info_uses_license_file_sources' (17338) panicked at src/module_writer/mock_writer.rs:148:5:
assertion `left == right` failed
  left: [77, 73, 84, 32, 76, 105, 99, 101, 110, 115, 101]
 right: [77, 73, 84, 32, 76, 105, 99, 101, 110, 115, 101, 32, 45, 32, 119, 111, 114, 107, 115, 112, 97, 99, 101, 32, 108, 101, 118, 101, 108]
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace


failures:
    module_writer::mock_writer::write_dist_info_uses_license_file_sources

test result: FAILED. 187 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.86s

error: test failed, to rerun pass `--lib`

Full build and check log:
maturin-1.13.1-1-x86_64-build.log
maturin-1.13.1-1-x86_64-check.log

As I haven't changed anything else in the build script, I assume this is some form of regression and would be happy for any input on how to resolve this!

Your maturin version (maturin --version)

1.13.0

Your Python version (python -V)

3.14.3

Your pip version (pip -V)

26.0.1

What bindings you're using

None

Does cargo build work?

• Yes, it works

If on windows, have you checked that you aren't accidentally using unix path (those with the forward slash /)?

• Yes

Steps to Reproduce

https://gitlab.archlinux.org/archlinux/packaging/packages/maturin/-/blob/e2030ec0c353dfddc41c74c9558122c6961e04a2/PKGBUILD