Tvheadend

Hitting a build failure as soon as I add --enable-pngquant option.

Cross-compiling on synology NAS using spksrc repository.
pngquant is available properly linked to shared libimagequant (also tried using static with no change).

Here is the end of the build output:
CC src/descrambler/dvbcam.o
CC src/input/mpegts/linuxdvb/linuxdvb_ddci.o
CC src/descrambler/algo/libaesdec.o
CC src/descrambler/algo/libaes128dec.o
CC src/descrambler/algo/libdesdec.o
MKBUNDLE bundle.c
Traceback (most recent call last):
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 201, in <module>
idx = add_entry(ents)
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 180, in add_entry
tmp = add_entry(ents[k], d, k, idx, p)
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 180, in add_entry
tmp = add_entry(ents[k], d, k, idx, p)
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 180, in add_entry
tmp = add_entry(ents[k], d, k, idx, p)
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 180, in add_entry
tmp = add_entry(ents[k], d, k, idx, p)
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 174, in add_entry
output_file(d, k, idx+1, p)
File "/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/support/mkbundle", line 92, in output_file
stdin=fd, stdout=fd, stderr=fd)
File "/usr/lib/python2.7/subprocess.py", line 394, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1047, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
Makefile:834: recipe for target '/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/build.linux/bundle.c' failed
make[3]: *** [/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5/build.linux/bundle.c] Error 1
make[3]: Leaving directory '/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend/work-apollolake-6.1/tvheadend-git221c29b40b1e53ae09a69d9458442dd4fea665f5'
../../mk/spksrc.compile.mk:36: recipe for target 'compile_target' failed
make[2]: *** [compile_target] Error 2
make[2]: Leaving directory '/home/spksrc/git-ffmpeg-next/spksrc/cross/tvheadend'
../../mk/spksrc.depend.mk:44: recipe for target 'depend_target' failed
make[1]: *** [depend_target] Error 2
make[1]: Leaving directory '/home/spksrc/git-ffmpeg-next/spksrc/spk/tvheadend'
../../mk/spksrc.spk.mk:463: recipe for target 'arch-apollolake' failed
make: [arch-apollolake] Error 2 (ignored)