error: link modifiers combination +bundle,+whole-archive is unstable when generating rlibs

[CarlSchwan]

Compiling qml-features v0.1.0 (/home/cschwan/kde/cxx-qt/examples/qml_features/rust)
error: link modifiers combination `+bundle,+whole-archive` is unstable when generating rlibs

tested with rust from the fedora repo and from rustup.

[ahayzen-kdab]

So looking at https://doc.rust-lang.org/rustc/command-line-arguments.html#-l-link-the-generated-crate-to-a-native-library +bundle is set by default, so that is likely where that is set.

Then we are normally building to staticlib with the Rust parts, i wonder which part specifically is being built to an rlib and if that's a problem.

This from initial investigation seems to have broken via a newer rustc ?

[ahayzen-kdab]

Manually setting cc_builder_whole_archive.link_lib_modifier("-bundle"); to still allow +whole-archive solves the issue.

But we need to check that

• Is it right that a rlib is being built there?
• Is setting -bundle OK or does that cause other problems?

@Be-ing ^^ any opinions ?

[Be-ing]

rust-lang/rust#108081 🤔

[Be-ing]

This is caused by a regression in rustc 1.69: rust-lang/rust#110912

Reopening this until the upstream issue is fixed

[Be-ing]

Upstream fix: rust-lang/rust#110917

[Be-ing]

Fix was merged upstream and will be in Rust 1.71 and maybe 1.70.

[ahayzen-kdab]

@Be-ing do we want to leave this open as a reminder to remove the workaround ? And also do we want to remove the workaround at some point ? How long should we wait for people to move on from 1.69 to 1.70+ ? Or is it even possible to have a cfg flag for a specific rustc version ?

[Be-ing]

The workaround is harmless AFAIK, so we might as well leave it forever.

[ahayzen-kdab]

Cool, just wanted to check :-)

[Be-ing]

We could remove the workaround if we raise the MSRV to >= 1.70 in the future (or 1.71 if the fix doesn't make it into 1.70).

[Be-ing]

rust-lang/rust#110917 was approved for backporting to 1.70.