Rich,

> Are you using static or dynamic linking?

Dynamic. Before posting here, I checked the musl source 
code, and the binary:

'objdump -z -d hello' gives: callq 4003e0 <dladdr@plt>

Further, 'musl-gcc -static hello.c -o hello_s' weights
23KB while the shared binary above weights only 7KB.

Finally, my example provided the compilation/linking 
cmd line, which, by default, is dynamic:

   // glibc:
   // gcc hello.c -o hello -ldl

   // musl:
   // musl-gcc hello.c -o hello

I am attaching the source code linked with musl 0.9.8
so you can duplicate this issue without wasting time.

Besides knowing how to enable dladdr() in dynamic mode,
I am interested in knowing what other steps are needed
beyond replacing the #ifdef SHARED by another custom 
define (#ifdef __FORCE_DL) for musl's dl implementation
to do the job in static binaries (with exported symbols).

Thank you for musl, a much-needed alternative.

Pierre