build.zig.zon file .hash does not include executable bit in practice

[emidoots]

Zig Version

0.11.0-dev.3890+43c98dc11

Steps to Reproduce and Observed Behavior

I was implementing a tool in Go to calculate/update build.zig.zon file hashes. While doing this, I noticed that the Zig implementation in src/Package.zig currently doesn't include executable file bit information in practice.

If I download/extract this tarball using my system tar extractor, you can see we have at least two executable files in it:

freetype-26f9ea0ce8ec934d9d53caec80f6b3d0f857892b % ls -lah *.sh
-rwxrwxr-x  1 slimsag  staff   248B Jun 29 01:13 update.sh
-rwxrwxr-x  1 slimsag  staff   318B Jun 29 01:13 verify.sh

However, if I modify this code in the stdlib to print the file hash and result of isExecutable:

zig/src/Package.zig

Line 718 in 0a6cd25

hasher.update(&.{ 0, @intFromBool(try isExecutable(file)) });

Then we find isExecutable always returns false:

update.sh: 3ade16b05234cffff8aa60857d4ee2f1a90698da63e908148aefe45242ae8075 - false
verify.sh: 7359f08ae3202633064963b58058ef193d2f358c28abe08c035550e3bad8571e - false

This appears to be due to this TODO during tar extraction:

zig/src/Package.zig

Lines 603 to 611 in 0a6cd25

	try std.tar.pipeToFileSystem(out_dir, decompress.reader(), .{
	.strip_components = 1,
	// TODO: we would like to set this to executable_bit_only, but two
	// things need to happen before that:
	// 1. the tar implementation needs to support it
	// 2. the hashing algorithm here needs to support detecting the is_executable
	// bit on Windows from the ACLs (see the isExecutable function).
	.mode_mode = .ignore,
	});

Importantly, this applies to all unix platforms too - not just windows - so once this is fixed, everyone's build.zig.zon file hashes will change.

Expected Behavior

build.zig.zon hashes include executable bit information in them

[squeek502]

I believe 1. in the TODO comment would be addressed by #15382

[andrewrk]

Note the plan for this is #17463 (comment) and the hashes will be unchanged, continuing to not include the executable bit. All ELF files and files with shebang lines will be given +x regardless of the executable bit in the tarball.

[andrewrk]

Fixed by 34bb670.