Making all in external/bdwgc
make[2]: Entering directory '/home/jook/mono/mono/external/bdwgc'
make[3]: Entering directory '/home/jook/mono/mono/external/bdwgc'
depbase=`echo extra/gc.lo | sed 's|[^/]*$|.deps/&|;s|\.lo$||'`;\
/bin/bash ./libtool  --tag=CC   --mode=compile arm-linux-gnueabi-gcc -DHAVE_CONFIG_H   -I./include -I./include  -DGC_PTHREAD_START_STANDALONE    -fexceptions -Wall -Wextra -Wpedantic -Wno-long-long -mfloat-abi=soft -fno-strict-aliasing  -MT extra/gc.lo -MD -MP -MF $depbase.Tpo -c -o extra/gc.lo extra/gc.c &&\
mv -f $depbase.Tpo $depbase.Plo
libtool: compile:  arm-linux-gnueabi-gcc -DHAVE_CONFIG_H -I./include -I./include -DGC_PTHREAD_START_STANDALONE -fexceptions -Wall -Wextra -Wpedantic -Wno-long-long -mfloat-abi=soft -fno-strict-aliasing -MT extra/gc.lo -MD -MP -MF extra/.deps/gc.Tpo -c extra/gc.c  -fPIC -DPIC -o extra/.libs/gc.o
In file included from ./include/private/gc_priv.h:254,
                 from ./include/private/dbg_mlc.h:28,
                 from extra/../backgraph.c:15,
                 from extra/gc.c:39:
./include/private/gc_atomic_ops.h:105:11: fatal error: atomic_ops.h: No such file or directory
 # include "atomic_ops.h"
           ^~~~~~~~~~~~~~
compilation terminated.