qtwebengine build fails on too-long filename with symlink

ExecutorElassus

So, somewhat messy situation:

/var/tmp/portage is on its own partition, which is 9.5GB and can't be expanded. dev-qt/qtwebengine thus fails the minimum-storage check and refuses to build. To solve this, I've created the symlink /var/tmp/portnotmp, which points to a subdirectory on another partition.

However, late in the qtwebengine build process it reaches a point where ninja fails because the file it's building includes the entire file path in its name, and this creates a filename that's greater than the 255-character limit of the filesystem.

How can I work around this problem?

Cheers,

E

Ionen · Developer Joined: 06 Dec 2018 Posts: 2933

Don't know where that's pointing to and how long it is, but try to have PORTAGE_TMPDIR point to the real directory rather than do a symlink (symlinked tmpdirs been flaky with qtwebengine especially, don't recommend it either way).

You can also permanently set that per-package using package.env:
https://wiki.gentoo.org/wiki//etc/portage/package.env#Build_certain_packages_in_a_different_location

If really needed to shorten the path (if that mount point is really deep), there'd be the option to do a mount -o bind mount I guess.

ExecutorElassus · Posted: Sat Jun 07, 2025 12:37 pm Post subject:

It's a deep enough subdirectory that the build fails (and symlinking doesn't seem to make any difference, as the build just uses the full path of the link target regardless). I have qtwebengine specifically set to use that directory in package.env, as instructed. I do not have any higher-level subdirectories/mount points with >10GB space on them, except for /usr (but that seems really risky to use, since I can't easily delete much of what resides there if I end up running out of space).

This is apparently a long-standing issue with Qt, noted here.

I'll look into using the bind option to see if that helps.

UPDATE: yup, bind-mounting that directory worked. So I guess I'll just have to mount that subdirectory whenever qtwebengine needs to build. Thanks for the help!

Cheers,

EE