ci: make Cachix push optional to support fork PRs#5931
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Fork PRs don't receive repository secrets, so `cachix watch-exec` fails with NoSigningKey before tests start. Skip the push wrapper when CACHIX_AUTH_TOKEN is empty; read-only cache access still works via the substituter configured by `cachix use`. Made-with: Cursor
Made-with: Cursor
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Very nice! |
ggreif
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Mar 26, 2026
## Problem
Fork PRs don't receive repository secrets. When `CACHIX_AUTH_TOKEN` is
empty, `cachix watch-exec` fails with a `NoSigningKey` error before
tests even start, blocking all CI for external contributors.
## Solution
Make the `cachix watch-exec` wrapper conditional in the test blueprint
action. When the auth token is absent (fork PR), run
`nix-build-uncached` directly without the push wrapper.
- The `cachix-action` step already handles an empty token gracefully —
it configures read-only substituter access via `cachix use`, so cached
derivations are still fetched.
- Only the push of newly-built derivations is lost, which is acceptable
for fork PRs.
- The token is passed via an `env` variable (not inline) to avoid
leaking it in logs.
- No caller changes needed — `${{ secrets.CACHIX_AUTH_TOKEN }}`
naturally resolves to empty for fork PRs.
Motivated by PR #5929.
Made with [Cursor](https://cursor.com)
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Problem
Fork PRs don't receive repository secrets. When
CACHIX_AUTH_TOKENis empty,cachix watch-execfails with aNoSigningKeyerror before tests even start, blocking all CI for external contributors.Solution
Make the
cachix watch-execwrapper conditional in the test blueprint action. When the auth token is absent (fork PR), runnix-build-uncacheddirectly without the push wrapper.cachix-actionstep already handles an empty token gracefully — it configures read-only substituter access viacachix use, so cached derivations are still fetched.envvariable (not inline) to avoid leaking it in logs.${{ secrets.CACHIX_AUTH_TOKEN }}naturally resolves to empty for fork PRs.Motivated by PR #5929.
Made with Cursor