Bootcycle build on macosx fails with the following error:

make[4]: *** No rule to make target '/opt/jprt/T/P1/182751.amurillo/s/build/macosx-x86_64-normal-server-fastdebug/bootcycle-build/support/modules_libs/java.base/server/libjsig.dylib', needed by 'all'. Stop.
make[3]: *** [import-hotspot] Error 2
make[2]: *** [bootcycle-images] Error 2
make[2]: Leaving directory '/opt/jprt/T/P1/182751.amurillo/s/make'
Makefile:136: recipe for target 'main-wrapper' failed
make[1]: *** [main-wrapper] Error 2

Further up the log, this is caused by the bootcycle-build/hotspot/dist/jre/lib directory being empty. The failing line is this:

BUILT_LIPO_FILES="`find /opt/jprt/T/P1/182751.amurillo/s/build/macosx-x86_64-normal-server-fastdebug/bootcycle-build/hotspot/dist/jre/lib/{i386,amd64}//opt/jprt/T/P1/182751.amurillo/s/build/macosx-x86_64-normal-server-fastdebug/bootcycle-build/hotspot/dist/jre/lib/libjsig.dylib 2>/dev/null`" || test $? = "1"; \
if [ -n "${BUILT_LIPO_FILES}" ]; then \
  mkdir -p /opt/jprt/T/P1/182751.amurillo/s/build/macosx-x86_64-normal-server-fastdebug/bootcycle-build/hotspot/dist/jre/lib; \
  lipo -create -output /opt/jprt/T/P1/182751.amurillo/s/build/macosx-x86_64-normal-server-fastdebug/bootcycle-build/hotspot/dist/jre/lib/libjsig.dylib ${BUILT_LIPO_FILES}; \
fi

Note that there is an extra space between find and the '/opt...' path. This extra space makes a subst fail in make and no files are found to run lipo on.