Initially reported by SuperSandro2000 at https://github.com/metabrainz/musicbrainz-docker/pull/123#discussion_r381977648

make: pkg-config: Command not found
cp sql/musicbrainz_collate.sql sql/musicbrainz_collate–1.0.0.sql
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fno-omit-frame-pointer -fPIC  -I. -I./ -I/usr/include/postgresql/9.5/server -I/usr/include/postgresql/internal -Wdate-time -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -I/usr/include/libxml2  -I/usr/include/mit-krb5  -c -o musicbrainz_collate.o musicbrainz_collate.c
make: pkg-config: Command not found
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fno-omit-frame-pointer -fPIC -shared -o musicbrainz_collate.so musicbrainz_collate.o -L/usr/lib/x86_64-linux-gnu  -Wl,-z,relro -Wl,-z,now  -L/usr/lib/x86_64-linux-gnu/mit-krb5 -Wl,--as-needed
0

We don't fail if it can't compile. This is the reason why the image built without pkg-config and I did not look very closely into the log.

And at https://github.com/metabrainz/musicbrainz-docker/pull/123#discussion_r381984825

It seems to compile without the dev libs as strangely the .h are already there.
The logs are also clean.