PSA: QLTY Cloud Custom Rubocop Cops need to be listed as config_files and only the basename, not the relative path!

[gwpantazes]

Question

PSA for those who may encounter the same issue. If you have any custom Rubocop cops, the way that you reference them in the qlty.toml is via the rubocop plugin's config_files array, but ONLY as a basename for the file.

For example, for a file that is in lib/cops/style/my_custom_cop.rb, you would ONLY put the basename my_custom_cop.rb into the config_files.

[[plugin]]
name = "rubocop"
...
config_files = [
  "my_custom_cop.rb",
]

If you incorrectly use a full relative path, then Rubocop will fail to load the cop in the QLTY Cloud sandboxed runner.

2026-01-27T16:51:35Z ERROR [T32] qlty_check::executor::invocation_result (10.6 MB): NURihi: rubocop/format STDERR: cannot load such file -- /home/runner/tmp/qlty/2EffcLPg-rw/./lib/cops/style/my_custom_cop.rb

How to reproduce (optional)

Using a relative path in Rubocop plugin config_files array causes a build failure.

Expected behavior (optional)

Using only the file's base name, even if it's within subdirectories, will work correctly.

CLI Version

QLTY Cloud

Information about Qlty configuration and environment (optional)

No response