Hi,

The Linux kernel's /proc/filesystems is an impurity in the Guix build
environment.  Its contents can cause the same derivation to behave
differently on different systems.

For example, the default kernel on Fedora systems uses SELinux, so
/proc/filesystems contains "selinuxfs".  However, the default kernel on
Guix System does not use SELinux, so /proc/filesystems does not contain
"selinuxfs".  This causes the sed derivation to fail when run on Fedora,
but not on Guix System:

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=41498

Can we avoid this problem somehow?  For example, is there a way to
normalize /proc/filesystems in the build environment?

We have the --impersonate-linux-2.6 option as a way to eliminate a
similar kind of impurity, but that option doesn't actually change the
contents of /proc/filesystems at all.  I tried it.

-- 
Chris