There are two versions of the psc-interpreter-locks.{ads,adb} files. The Makefile and the interpreter/config.sh script are supposed to choose one of the two depending on the state of the OMP flag. It looks like the Makefile dependence is confused, as it seems to be associating the link_names rather than the locks file with the config script. I would change the following lines in the Makefile:
config: semantics/psc-link_names.ads
<tab>cd interpreter; ./config.sh $(OMP)
with:
config: interpreter/psc-interpreter-locks.ads semantics/psc-link_names.ads
interpreter/psc-interpreter-locks.ads : interpreter/config.sh
<tab>cd interpreter; ./config.sh $(OMP)
If you can't get that to work, you can just run interpreter/config.sh by hand, with the appropriate value for OMP (either "on" or "off"), depending on whether you want to use the OpenMP version of locks (OMP=on), or the version based on a protected object (OMP=off).
It is somewhat bizarre that the Makefile has had this bug for so long!
Take care,
-Tuck