Ubuntu 18.04 how to recover from libgcc_s.so.1 dissaster

Ubuntu18_04_libgcc_s_so_1_recovery.md

Motivation

When:

• using newer compilers from Ubuntu test ppa (e.g. ppa:ubuntu-toolchain-r/test)
• ppa-purge later to revert the system to clean state

it is possible to get to dissastrous state where libgcc_s.so.1 is misssing.

In such state apt and other applications may not work and system will not boot.

Workaround

Boot to recovery terminal.

Locate ligcc_so.so.1 on your system (if you are lucky):

find / -name libgcc_s.so.1 2>/dev/null

Copy it (or link) to location where it is expected

cp your_path /lib/x86_64-linux-gnu/libgcc_s.so.1

After that your system should boot and apt should work.

Alternatively:

• copy from other machine
• check /var/cache/apt/archives, you may still have deb package to install it from

Cleanup

On a clean Ubuntu 18.04 machine it is possible to check where file comes from:

# on clean Ubuntu 18.04 machine
dpkg -S /lib/x86_64-linux-gnu/libgcc_s.so.1
# in my case:
# libgcc1:amd64: /lib/x86_64-linux-gnu/libgcc_s.so.1

Reinstall this package on your now working machine:

 sudo apt-get --reinstall install libgcc1:amd64

This step is important if you do some deb packaging on your system. (you need sound apt state, able to track dependencies correctly)