rustc cannot statically link to C library

[vks]

When trying to link to a static C library called md

rustc src/lib.rs [...] -L native=/path/to/md -l static=md

it fails:

error: linking with `cc` failed: exit code: 1
[...]
note: /usr/bin/ld: /path/to/md/libmd.a(acosh.o): relocation R_X86_64_32 against `.data' can not be used when making a shared object; recompile with -fPIC
/path/to/md/libmd.a(acosh.o): error adding symbols: Bad value
collect2: error: ld returned 1 exit status

error: aborting due to previous error

I don't understand why rustc tries making a shared object. Changing the argument to -l dylib does not make any difference.

[vks]

How to reproduce:

$ git clone https://github.com/vks/special-fun.git
$ cd special-fun
$ cargo build  # works
[...]
$ cargo test  # fails
[...]

Maybe it is related to rustc --test?

[alexcrichton]

This is actually working as intended because rustc produces position-independent output by default (even for executables, not just for dynamic libraries). You'll need to add -fPIC to your makefiles for the native library or use a build dependency like gcc to build native code.

[vks]

Is it possible to make it produce non position-independent output?

[alexcrichton]

Yes rustc -C relocation-model=static should lift this requirement.