>It then runs bmake -f Makefile install, which builds the lst*.o files in the
>main bmake directory, but does not remove them.

>If you run the bootstrap script a second time, makefile.boot again builds
>objects in the lst.lib sub-directory, but its naive link command just uses
>*.o lib/*.o, which picks up both the newly built lst/*.o files and the lst*.o
>files left around from last time, and hence fails with multiply defined
>symbols.

FWIW the boot-strap script which comes with recent bmake versions does
${MAKE:-make} -f makefile.boot clean
before doing anything else.  To cover this case.

--sjg