Issue: Tectonic command fails on Rocky Linux 8.7 (AMD64)

[MIngPAPA]

Description
When running the tectonic --help command on a Rocky Linux 8.7 system with an AMD64 architecture, the following errors are encountered:

tectonic: /lib64/libm.so.6: version `GLIBC_2.35' not found (required by tectonic)
tectonic: /lib64/libm.so.6: version `GLIBC_2.29' not found (required by tectonic)
tectonic: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.30' not found (required by tectonic)
tectonic: /lib64/libc.so.6: version `GLIBC_2.32' not found (required by tectonic)
tectonic: /lib64/libc.so.6: version `GLIBC_2.29' not found (required by tectonic)
tectonic: /lib64/libc.so.6: version `GLIBC_2.34' not found (required by tectonic)
tectonic: /lib64/libc.so.6: version `GLIBC_2.33' not found (required by tectonic)

Environment
Operating System: Rocky Linux release 8.7 (Green Obsidian)
Architecture: AMD64
glibc: glibc-2.28-236.el8_9.7.x86_64

[ahojukka5]

I can confirm the same problem with Rocky Linux 8.10. This issue should be taken seriously, as Rocky Linux is quite normal choice for HPC environments.

Well, there are a couple of ways to overcome this. Either build from source or use musl binaries that don't depend on glibc at all. Or change the build process or use some other build image.

The easiest way would be to add a note to the installation instructions stating that in case of glibc problems, the user should try the musl binary instead.

[ahojukka5]

--- drop-installer.sh.orig	2025-03-22 13:35:52.840283000 +0200
+++ drop-installer.sh	2025-03-22 13:35:48.898507000 +0200
@@ -129,6 +129,17 @@
         fi
         if ldd --version 2>&1 | grep -q 'musl'; then
             _clibtype="musl"
+        else
+            # Extract glibc version if not musl
+            glibc_version=$(ldd --version | head -n1 | awk '{print $NF}')
+            glibc_major=$(echo "$glibc_version" | cut -d. -f1)
+            glibc_minor=$(echo "$glibc_version" | cut -d. -f2)
+
+            if [ "$glibc_major" -eq 2 ] && [ "$glibc_minor" -lt 29 ]; then
+                say "Detected GLIBC version $glibc_version — too old for the gnu binary (requires ≥ 2.29)."
+                say "Falling back to musl binary for compatibility."
+                _clibtype="musl"
+            fi
         fi
     fi

Perhaps something like this would make things work? I can confirm that this works on Ubuntu 22.04 and Rocky Linux 8.10. I can create PR if it looks good.