app-compat: Not a directory error and assertion failure when running gzip with app-elfloader

[razvand]

Describe the bug

When using app-elfloader (via the run_app.sh script in run-app-elfloader) to run the gzip dynamic build and the gzip static PIE build, a Not a directory error appears based on a utimensat system call.

Also, a dentry-related assertion appears. This is also part of the echo dynamic build and the ls dynamic build.

Steps to reproduce

You can easily just use the ./do.sh script in the unikraft-upb/scripts repository:

$ ./do.sh setup
$ ./do.sh build
$ ./do.sh run_built gzip
$ ./do.sh run_built gzip_static

Expected behavior

There shouldn't be any errors printed.

Which architectures were you using or does this bug affect?

x86_64

Which platforms were you using or does this bug affect?

kvm

Relevant log output

write(fd:4, "\x1F\x8B\x08\x08gjBd\x00\x03test.txt\x00+I-.\xE1"..., 34) = 34
close(fd:3) = OK
utimensat(0x4, 0x0, ...) = Not a directory (-20)
gzip: write(fd:2, "gzip: ", 6) = 6
/test.txt.gz: Not a directory
write(fd:2, "/test.txt.gz: Not a dire"..., 30) = 30
fchown(0x4, 0x0, ...) = 0x0
fchmod(0x4, 0x1b4, ...) = 0x0
close(fd:4) = OK
rt_sigprocmask(0x0, 0x100021a600, ...) = 0x0
unlink(0x100021dd00, 0x100021a600, ...) = 0x0
rt_sigprocmask(0x2, 0x47f92f7d0, ...) = 0x0
lseek(0x0, 0x0, ...) = 0x0
close(fd:0) = OK
[    0.327286] CRIT: [libvfscore] <dentry.c @  216> Assertion failure: dp->d_refcnt > 0

[marcrittinghaus]

I can reproduce the assert. Looking into it...