fix(repack): enforce mode=a=rX,u+w to avoid permission discrepancies

[ssnaaz]

Archives created on different systems had varying file permissions, leading to different checksums after repacking. Setting mode=a=rX,u+w to normalize permissions to ensure reproducibility.

Fixes: 6c54581 (chore(repack): create tar with stable order and owner)

[Urist-McGit]

The commit message should be fix(repack): enforce mode=755 to avoid permission discrepancies

[ssnaaz]

@Urist-McGit Updated, thanks!

[fmoessbauer]

This makes all files executable. We instead need either --mode=a=rX,u+w (1) or --mode=go+u,go-w (2)

1. https://reproducible-builds.org/docs/archives/
2. https://www.gnu.org/software/tar/manual/html_section/Reproducibility.html

[ssnaaz]

Thanks @fmoessbauer, I have verified both options: --mode=a=rX,u+w and --mode=go+u,go-w and both work as expected. However, I chose the first option (a=rX,u+w) because it best addresses our issue: on system A the permission is rw-rw-r--, whereas on system B it is rw-r--r--, ensuring reproducible file modes across systems. Please let me know if my assumption is correct and kindly review this change.

[fmoessbauer]

Thanks @fmoessbauer, I have verified both options: --mode=a=rX,u+w and --mode=go+u,go-w and both work as expected. However, I chose the first option (a=rX,u+w) because it best addresses our issue: on system A the permission is rw-rw-r--, whereas on system B it is rw-r--r--, ensuring reproducible file modes across systems. Please let me know if my assumption is correct and kindly review this change.

That makes sense. Thanks. Merged.