Also solver/$INPATH is subset of */$INPATH.

Use \ instead of / in path, but more importantly,
use relative path, because '-' in path caused build error.
Path was truncated right before the '-'. We could have put it
between quotes, but then the SO_ACTIVEX_TLB_DIR define would not
be substituted, so instead of hacking of the rc, I chose this
solution.

e

...something better is required (getting rid of the solar mutex?).