I made a change to my FUSE driver to set -o fsname to the path of the file system image. This works fine on Linux / FreeBSD and also on macOS. However, the unit test I added failed in CI, and when looking at the output that file system image path was truncated after 89 characters.

I tried to replicate this with a previous version of the driver that didn't set fsname and setting a long string manually:

$ dwarfs data.dwarfs mnt -ofsname=/Volumes/opensource/artifacts/dwarfs/builds/1831.1-0.13.0-333-g0c147d2c54/converter_benchmark-0.13.0-333-g0c147d2c54-Linux-aarch64-clang-musl

With that, the output of mount becomes:

$ mount
[...]
/Volumes/opensource/artifacts/dwarfs/builds/1831.1-0.13.0-333-g0c147d2c54/converter_bench on /Users/mhx/git/github/dwarfs/build/mnt (macfuse, nodev, nosuid, synchronous, mounted by mhx)

So clearly, the fsname is truncated somewhere; but it is unclear if this happens in macFUSE, macOS, or the mount output.

This is with macFUSE 4.8.3 on macOS 14.8.1.