This was originally reported on build-dev here:
http://mail.openjdk.java.net/pipermail/build-dev/2018-December/024266.html

Building the bootcycle-images target at revision 9745e4e36dd1 with LOG=debug fails as follows:

FindJtregGroups /disk/openjdk/upstream-sources/openjdk-head/test/hotspot/jtreg
FindJtregGroups /disk/openjdk/upstream-sources/openjdk-head/test/jdk
FindJtregGroups /disk/openjdk/upstream-sources/openjdk-head/test/langtools
FindJtregGroups /disk/openjdk/upstream-sources/openjdk-head/test/nashorn
FindJtregGroups /disk/openjdk/upstream-sources/openjdk-head/test/jaxp
make/Main.gmk:1087: *** target pattern contains no '%'. Stop.
gmake[4]: Leaving directory '/disk/openjdk/upstream-sources/openjdk-head'

ERROR: Build failed for target 'product-images' in configuration 'linux-x86_64-server-release' (exit code 2)
gmake[4]: Entering directory '/disk/openjdk/upstream-sources/openjdk-head'
gmake[4]: warning: -jN forced in submake: disabling jobserver mode.

Building bootcycle-images with LOG=info works. This is another incarnation of JDK-8213736

The work-around is to pass --no-print-directory to the top level make invocation.