`snap run ruby.gem` fails with `undefined symbol`

[maxkapur]

Came here from #14, but my issue is even broader—I can't run the gem command from the snap at all:

> snap run ruby.gem --help
ruby: symbol lookup error: /snap/core20/current/lib/x86_64-linux-gnu/libpthread.so.0: undefined symbol: __libc_pthread_init, version GLIBC_PRIVATE

apt installing everything that comes up in apt search libpthread did not help.

Installation details:

> snap run ruby --version
ruby 3.4.4 (2025-05-14 revision a38531fd3f) +PRISM [x86_64-linux]
> snap --version
snap    2.68.4
snapd   2.68.4
series  16
ubuntu  25.04
kernel  6.14.0-15-generic

[hsbt]

I could reproduce that with Ubuntu 24.04.

$ /snap/bin/ruby.gem -v
ruby: symbol lookup error: /snap/core20/current/lib/x86_64-linux-gnu/libpthread.so.0: undefined symbol: __libc_pthread_init, version GLIBC_PRIVATE

I'll look this.

[hsbt]

I tried to update base image to core22 or core24 from core20. But they are not working now. I need to additional investigation.

[hsbt]

@maxkapur Sorry too late response. I released Ruby 3.4.5 as version 426. That seems works fine with Ubuntu 24.04.

ubuntu@tk2-119-60130:~$ snap list
Name       Version   Rev    Tracking         Publisher   Notes
core20     20250526  2599   latest/stable    canonical✓  base
core22     20250612  2045   latest/stable    canonical✓  base
ruby       3.4.5     426    latest/stable    rubylang✓   classic
snapcraft  8.3.2     12378  latest/stable/…  canonical✓  classic
snapd      2.70      24792  latest/stable    canonical✓  snapd

ubuntu@tk2-119-60130:~$ snap run ruby -v
ruby 3.4.5 (2025-07-16 revision 20cda200d3) +PRISM [x86_64-linux]

ubuntu@tk2-119-60130:~$ snap run ruby.gem -v
3.6.9

Could you try that?

[maxkapur]

Thank you @hsbt. Unfortunately this is giving me a different error. Like the original, the issue seems to arise only when the deb and snap packages are installed simultaneously:

$ sudo apt update -y
$ sudo apt upgrade -y
$ sudo apt install ruby-full -y
$ sudo snap install --classic ruby
$ snap run ruby.gem -v
/snap/ruby/426/lib/ruby/3.4.0/x86_64-linux/rbconfig.rb:13:in `<module:RbConfig>': ruby lib version (3.4.5) doesn't match executable version (3.2.3) (RuntimeError)
        from /snap/ruby/426/lib/ruby/3.4.0/x86_64-linux/rbconfig.rb:11:in `<top (required)>'
        from /snap/ruby/426/lib/ruby/3.4.0/rubygems.rb:9:in `require'
        from /snap/ruby/426/lib/ruby/3.4.0/rubygems.rb:9:in `<top (required)>'
        from <internal:gem_prelude>:2:in `require'
        from <internal:gem_prelude>:2:in `<internal:gem_prelude>'

More info:

$ snap version
snap    2.70
snapd   2.70
series  16
ubuntu  24.04
kernel  6.8.0-45-generic
$ ruby -v
ruby 3.2.3 (2024-01-18 revision 52bb2ac0a6) [x86_64-linux-gnu]
$ snap run ruby -v
ruby 3.4.5 (2025-07-16 revision 20cda200d3) +PRISM [x86_64-linux]
$ snap list
Name    Version   Rev    Tracking       Publisher   Notes
core22  20250612  2045   latest/stable  canonical✓  base
ruby    3.4.5     426    latest/stable  rubylang✓   classic
snapd   2.70      24792  latest/stable  canonical✓  snapd

[hsbt]

It seems to mix system ruby provided by apt-line. Could you remove that and try again?

[maxkapur]

This bug is specifically about the case when the ruby deb and snap are both installed. See https://bugs.ruby-lang.org/issues/21397.

[hsbt]

I didn't investigate that yet. Unfortunately, I will not fix that situation because that is no sense to mix multiple Ruby interpreter in the real use-case.

[maxkapur]

Thank you. In that case, would you be willing to re-open the bug on ruby-lang.org (or change the reason for closing there as well)? Many Ubuntu images (e.g. GitHub Actions runners) come with the deb Ruby preinstalled, so this is not necessarily an unusual setup.