Guide: Steam Bus Error (Exit 135) - BTRFS Filesystem Corruption

[Vonzedlitz]

Symptoms:

• Steam fails to launch with "Bus error (core dumped)"
• ldconfig crashes with exit status 135
• Terminal shows: steam-runtime-identify-library-abi: Cannot run ldconfig: wait status 135

Root Cause:
BTRFS filesystem corruption affecting a critical 32-bit system library (/usr/lib32/libnss_mymachines.so.2). When Steam or ldconfig tried to read this corrupted library, it caused a bus error crash.

Diagnosis Steps:

• Verify ldconfig is crashing:

/sbin/ldconfig -XNv
   echo $?

If this returns 135 or crashes, ldconfig itself is failing.

• Check for filesystem corruption:

sudo dmesg | grep -i "corrupt"

Look for BTRFS checksum errors like:

BTRFS warning (device dm-0): csum failed root 308 ino 825611
BTRFS error (device dm-0): bdev /dev/mapper/root errs: ... corrupt 525 ...

• Find the corrupted file:

sudo find / -inum <INODE_NUMBER> 2>/dev/null

Replace <INODE_NUMBER> with the inode from dmesg (e.g., 825611).

Fix:

• Identify and reinstall the corrupted package:

Find which package owns the corrupted file

   pacman -Qo /usr/lib32/libnss_mymachines.so.2

Reinstall it (usually lib32-systemd)

   sudo pacman -S lib32-systemd --overwrite '*'

• Run BTRFS scrub to repair filesystem:

sudo btrfs scrub start -B /
sudo btrfs scrub status /

• Verify ldconfig works:

/sbin/ldconfig -XNv
   echo $?

(Should return 0)

• Launch Steam:

steam