C sshnpd binary (from c0.1.8 release) won't run on Ubuntu 20.04 due to missing glibc dependency

[cpswan]

Describe the bug

Running ./sshnpd returns:

./sshnpd: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.33' not found (required by ./sshnpd)
./sshnpd: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.34' not found (required by ./sshnpd)

Steps to reproduce

1. First I downloaded the sshnp-linux-x64.tgz tarball from the c0.1.8 release
2. Then I extracted the binary: tar -xvf sshnp-linux-x64.tgz sshnpd
3. And then I run the binary ./sshnpd

Expected behavior

Daemon shows help

Additional context

uname -a

Linux DB4 5.15.153.1-microsoft-standard-WSL2 #1 SMP Fri Mar 29 23:14:13 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -a

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.6 LTS
Release:        20.04
Codename:       focal

ldd --version

ldd (Ubuntu GLIBC 2.31-0ubuntu9.16) 2.31
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.

[XavierChanth]

@cpswan This should hopefully solve this problem:
#1221

If not, then I will investigate further.

[cpswan]

@XavierChanth I've tried the binaries for your manual test build and the c0.1.9-rc1 release and they both still fail to run for the same reason as before

[cpswan]

This may deserve its own ticket, but I just had a go at building locally, and that's failing:

[ 50%] Linking C executable sshnpd
/usr/bin/ld: CMakeFiles/sshnpd.dir/src/main.c.o: in function `main':
main.c:(.text+0x8f2): undefined reference to `pthread_create'
/usr/bin/ld: main.c:(.text+0xcf2): undefined reference to `pthread_join'
/usr/bin/ld: _deps/srv-lib-build/libsrv-lib.a(srv.c.o): in function `run_srv_daemon_side_multi':
srv.c:(.text+0x8ee): undefined reference to `pthread_create'
/usr/bin/ld: srv.c:(.text+0x960): undefined reference to `pthread_detach'
/usr/bin/ld: _deps/srv-lib-build/libsrv-lib.a(srv.c.o): in function `socket_to_socket':
srv.c:(.text+0xdf9): undefined reference to `pthread_create'
/usr/bin/ld: srv.c:(.text+0xe63): undefined reference to `pthread_create'
/usr/bin/ld: srv.c:(.text+0xf3b): undefined reference to `pthread_join'
/usr/bin/ld: srv.c:(.text+0xfb1): undefined reference to `pthread_cancel'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/sshnpd.dir/build.make:113: sshnpd] Error 1
make[1]: *** [CMakeFiles/Makefile2:751: CMakeFiles/sshnpd.dir/all] Error 2
make: *** [Makefile:136: all] Error 2

My CMake line was:

cmake -B build -S . -DBUILD_SHARED_LIBS=off -DCMAKE_C_COMPILER=gcc -DCMAKE_C_FLAGS="-Wno-calloc-transposed-args -Wno-error -pthread -lrt"

[cpswan]

https://github.com/wheybags/glibc_version_header may help here

https://stackoverflow.com/a/76085075 also suggests using the zig compiler, which would tie into #1208

[cpswan]

With Zig ruled out as an approach I'll take a look at the glibc_version_header way of dealing with things.

[cpswan]

Alpine Linux: Effortless static linking and portable applications for C/C++ provides a good overview of the issue we're facing with glibc.

I've already spent some time getting a linux-x64/arm64 build working inside of Debian 10 (glibc 2.28.0) in Docker. Unfortunately doing the same for armv7 is challenging as both CMake and Clang aren't available.

Will also take a look at what we can do with musl (building inside Alpine).