Hi Lucas, Lucas Nussbaum skribis: > On 18/02/21 at 12:38 +0100, Ludovic Courtès wrote: [...] >> I tried grabbing mount options from there and reapplying them to the >> MS_REMOUNT call (patch below). However, that still doesn’t work: >> >> --8<---------------cut here---------------start------------->8--- >> 14273 mount("/gnu/store/mmhimfwmmidf09jw1plw3aw1g1zn2nkh-bash-static-5.0.16", "/tmp/guix-directory.Plgkgt//gnu/store/mmhimfwmmidf09jw1plw3aw1g1zn2nkh-bash-static-5.0.16", 0x236a4b0, MS_RDONLY|MS_REMOUNT|MS_BIND, "rw,nosuid,nodev,relatime") = -1 EPERM (Operation not permitted) >> --8<---------------cut here---------------end--------------->8--- > > That's strange: it worked in my manual tests. I investigated some more and can’t get it to work. Do you happen to have a working invocation or C snippet? Thanks, Ludo’.