Re: [gentoo-musl] realpath() gives wrong result on a chroot musl system

[Felix Janda]

Lei Zhang wrote:
> Hi,
>
> I was trying to run clang (built specifically for musl) on a chroot
> musl system, and met some strange issue. After some investigation, it
> turns out the function realpath() is giving me wrong results.
>
> I can reproduce the error with the following code snippet:
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <limits.h>
>
> int main(int argc, char** argv) {
>     const char* path = "/usr/bin/clang"; // suppose this is a valid path
>     char resolved[PATH_MAX];
>     char* ret = realpath(path, resolved);
>
>     if (ret)
>         printf("%s\n", ret);
> }
>
> If I build it against musl, it gives correct result on my host, but
> wrong result on chroot; If I build it against glibc (statically, since
> there's no glibc on chroot), it gives correct results on both
> environments. So it looks like musl is to blame on the chroot
> environment. I haven't yet confirmed if it's a bug.
>
> Any thoughts?

With musl, realpath() (and some other things) depend on having a
mounted /proc.

Felix