GLIBC problem on Ubuntu 22.04 (2.35 vs 2.38) - should go into the Documentation

[mxdpeep]

Docker builder for Ububtu 22.04 LTS

https://github.com/mxdpeep/docker_builder_dexed

[asb2m10]

I don't understand what is the issue, what is the glibc problem exactly ?

[mxdpeep]

you are building against a TOO modern glibc, so long term systems (LTS) can't run your binary

Ubuntu LTS release, 22.04 “Jammy Jellyfish”, will have you covered until April of 2032.23

The "glibc Forward-Compatibility" Trap

The issue isn't just a "version number"—it's about how Linux handles core system symbols.

1. The One-Way Street
glibc (the GNU C Library) is designed with backward compatibility, but zero forward compatibility.

A binary compiled on Ubuntu 20.04 (glibc 2.31) will run perfectly on Ubuntu 24.04 (glibc 2.39).

A binary compiled on Ubuntu 24.04 will crash on anything older (like Ubuntu 22.04 LTS or Debian 12) because it explicitly looks for versioned symbols (like GLIBC_2.38) that simply don't exist in the older library.

2. The "Symbol Versioning" Headache
When you compile Dexed on a bleeding-edge distro, the linker maps basic functions (like memcpy or math functions) to the newest versions available in your system's libc.so. If a user on an LTS system tries to load your plugin, the dynamic linker fails immediately with a version 'GLIBC_X.XX' not found error. The plugin won't even initialize.

3. Why Ubuntu 22.04 (Jammy) is the Sweet Spot
By using Ubuntu 22.04 as your Build Environment (e.g., in your GitHub Actions runner or a Docker container), you ensure that Dexed targets glibc 2.35.

Result: Your plugin will work for everyone on 22.04, 23.10, 24.04, and even future releases.

Bonus: You don't lose any modern features; you just ensure the binary interface remains compatible with the "Long Term Support" systems that most pro-audio users actually use for stability.

[asb2m10]

Ok now I understand, another user just sent a similar case of glibc issue, I'll downgrade the action agent for the build

[mxdpeep]

I'm already building myself, it's 4 minutes make

[mxdpeep]

BTW thank you for DEXED - DX7IID was my first synth ~1990 when I was 16 😎 still the best vibe, FM synthesis rocks

[asb2m10]

BTW thank you for DEXED - DX7IID was my first synth ~1990 when I was 16 😎 still the best vibe, FM synthesis rocks

Yes ! I love my DX7, it still charts to unknown territory if you want to explore.

The linux action build is now based on ubuntu-22.04