I just compiled lyx-1.0.2 the other day, so this is a new bug.
During make, I get...
cxx -c -g -I. -I. -I../images -I/opt/xforms/FORMS kbmap.C
cxx -c -g -I. -I. -I../images -I/opt/xforms/FORMS bmtable.C
cxx -c -g -I. -I. -I../images -I/opt/xforms/FORMS math_symbols.C
cxx -c -g -I. -I. -I../images -I/opt/xforms/FORMS lyxfunc.C
cxx: Error: ImportNoweb.h, line 43: Invalid pure specifier.
static const int BUFSIZE = 512;
-----------------------------------^
*** Exit 1
Stop.
*** Exit 1
Stop.
#
This is on a DecAlpha with Digital Unix 4.