···11+---
22+name: Unreproducible package
33+about: A package that does not produce a bit-by-bit reproducible result each time it is built
44+title: ''
55+labels: '0.kind: enhancement', '6.topic: reproducible builds'
66+assignees: ''
77+88+---
99+1010+Building this package twice does not produce the bit-by-bit identical result each time, making it harder to detect CI breaches. You can read more about this at https://reproducible-builds.org/ .
1111+1212+Fixing bit-by-bit reproducibility also has additional advantages, such as avoiding hard-to-reproduce bugs, making content-addressed storage more effective and reducing rebuilds in such systems.
1313+1414+### Steps To Reproduce
1515+1616+```
1717+nix-build '<nixpkgs>' -A ... --check --keep-failed
1818+```
1919+2020+You can use `diffoscope` to analyze the differences in the output of the two builds.
2121+2222+To view the build log of the build that produced the artifact in the binary cache:
2323+2424+```
2525+nix-store --read-log $(nix-instantiate '<nixpkgs>' -A ...)
2626+```
2727+2828+### Additional context
2929+3030+(please share the relevant fragment of the diffoscope output here,
3131+and any additional analysis you may have done)