X11 linking issue potentially musl libc related

Question

I am running Alpine Linux with musl libc attempting to install-
https://github.com/patrickhaller/no-wm/
with-
make install
I have musl-dev and libx11-dev installed.
libx11-dev puts libs in /usr/lib not /usr/X11/lib. see-
https://pkgs.alpinelinux.org/contents?branch=edge&name=libx11-dev&arch=x86&repo=main
So I changed the Makefile line to-
X11LIB = -lX11 -L/usr/lib/
I confirmed libX11.so is at that directory location.

Yet my install still fails with this output-

$ make install
gcc -O2 -Wall -std=c99 -pedantic -lX11 -L/usr/lib/ x-alt-tab-mru.c -o x-alt-tab-mru
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: /tmp/cckobJdo.o: in function `x_alt_tab':
x-alt-tab-mru.c:(.text+0x70): undefined reference to `XGetWMHints'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text+0x84): undefined reference to `XGetWindowAttributes'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text+0xec): undefined reference to `XLowerWindow'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text+0xf8): undefined reference to `XRaiseWindow'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text+0x10c): undefined reference to `XSetInputFocus'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text+0x11c): undefined reference to `XRestackWindows'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text+0x128): undefined reference to `XSync'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: /tmp/cckobJdo.o: in function `main':
x-alt-tab-mru.c:(.text.startup+0x34): undefined reference to `XOpenDisplay'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text.startup+0x44): undefined reference to `XSync'
/usr/lib/gcc/aarch64-alpine-linux-musl/10.2.0/../../../../aarch64-alpine-linux-musl/bin/ld: x-alt-tab-mru.c:(.text.startup+0x70): undefined reference to `XQueryTree'
collect2: error: ld returned 1 exit status
make: *** [Makefile:19: x-alt-tab-mru] Error 1

I've confirmed the headers in that x-alt-tab-mru.c file are present in the correct location and were included with libx11-dev.

What can I do next to troubleshoot this and get it to compile? I've chased down everything I could think of..

Answer 1

The order of arguments on the link command line is significant. -L options apply only to searching for libraries designated later on the command line, and, at least for static linking, undefined symbols in one object among those being linked are resolved only against other objects designated later on the command line. Behavior may (or may not) vary a bit when linking shared libraries, but to be safe, you should always order the objects to be linked (source files, object files, and libraries) according to their dependencies.

In particular, then,

• in the unlikely event that you need -L/usr/lib at all, it should come before -lX11, and
• the -lX11 option should appear after x-alt-tab-mru.c in the link command.