One of latest libdrm commits make libdrm fails to build on 32 bit Ubuntu 16.06.
Builds fine on 64 bit and newer Ubuntus. Error:

make[4]: Entering directory
'/<<BUILDDIR>>/libdrm-2.4.89+git1801270630.6f0f6c~oibaf~x/build/tests/amdgpu'
../../../tests/amdgpu/basic_tests.c: In function ‘amdgpu_userptr_test’:
../../../tests/amdgpu/basic_tests.c:1397:2: warning: ignoring return value of
‘posix_memalign’, declared with attribute warn_unused_result [-Wunused-result]
  posix_memalign(&ptr, sysconf(_SC_PAGE_SIZE), BUFFER_SIZE);
  ^
In file included from ../../../amdgpu/amdgpu_internal.h:35:0,
                 from ../../../tests/amdgpu/vm_tests.c:28:
../../../libdrm_macros.h: In function ‘drm_munmap’:
../../../libdrm_macros.h:79:4: error: size of unnamed array is negative
    STATIC_ASSERT(LARGE_OFF_T % 2147483629 == 721 &&
    ^
Makefile:616: recipe for target 'amdgpu_test-vm_tests.o' failed
make[4]: *** [amdgpu_test-vm_tests.o] Error 1
make[4]: Leaving directory
'/<<BUILDDIR>>/libdrm-2.4.89+git1801270630.6f0f6c~oibaf~x/build/tests/amdgpu'

Full build log including configure flags:
https://launchpadlibrarian.net/354844704/buildlog_ubuntu-xenial-i386.libdrm_2.4.89+git1801270630.6f0f6c~oibaf~x_BUILDING.txt.gz