Randomly breaks during multi-CPU build

[yurivict]

Builds fine on 1 CPU, but fails on multiple CPUs:

cc -c -o timecode.o -O2 -pipe -fno-omit-frame-pointer  -fstack-protector -isystem /usr/local/include -fno-strict-aliasing    `pkg-config --cflags libavcodec libavformat libavutil libswscale` timecode.c
export PKG_CONFIG_PATH=;\
cc -c -o vinfo.o -O2 -pipe -fno-omit-frame-pointer  -fstack-protector -isystem /usr/local/include -fno-strict-aliasing    `pkg-config --cflags libavcodec libavformat libavutil libswscale` vinfo.c
gmake[2]: *** No rule to make target '../libharvid/libharvid.a', needed by 'harvid'.  Stop.
gmake[2]: Leaving directory '/usr/ports/multimedia/harvid/work/harvid-0.8.2/src'
gmake[1]: *** [Makefile:7: src] Error 2
gmake[1]: *** Waiting for unfinished jobs....

[x42]

I recall seeing this a few years ago. The subdirs are all independently built..

Since this project only has a few sources and compiles + links in under 2 seconds, I left this as "won't fix". Parallel builds are not really needed and gnu/make does not use concurrency by default...
..but if you really must; build the stages separately: make -C libharvid -j10; make -j 10