Problem overriding ports with portshaker.

[George Hartzell]

I've been happily using portshaker to merge my "personal" ports tree
[1] with the standard tree, then building things with poudriere.  Up
until today the things in my tree were additions.

Today I tried replacing the standard copy of audio/logitechmusicserver
with a customized version that includes my SSL patch [2] and I suspect
I'll also need something like the Perl 5.30 patch [3].  I'm getting a
confusing error when I try to merge the trees:

```
hartzell at corvid:/usr/portshaker/github_hartzell_freebsd-ports/audio % sudo portshaker -M
make: "/usr/share/mk/bsd.port.mk" line 32: Cannot open /usr/ports/Mk/bsd.port.mk
make: "/usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver/Makefile" line 87: Malformed conditional (${ARCH} == "i386")
make: "/usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver/Makefile" line 94: Malformed conditional (${ARCH} == "amd64")
make: "/usr/share/mk/bsd.port.mk" line 32: Cannot open /usr/ports/Mk/bsd.port.mk
make: Fatal errors encountered -- cannot continue[: make: stopped in /usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver: bad number
make: "/usr/share/mk/bsd.port.mk" line 32: Cannot open /usr/ports/Mk/bsd.port.mk
make: "/usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver/Makefile" line 87: Malformed conditional (${ARCH} == "i386")
make: "/usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver/Makefile" line 94: Malformed conditional (${ARCH} == "amd64")
make: "/usr/share/mk/bsd.port.mk" line 32: Cannot open /usr/ports/Mk/bsd.port.mk
make: Fatal errors encountered -- cannot continue[: make: stopped in /usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver: bad number
[: make: stopped in /usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver: bad number
hartzell at corvid:/usr/portshaker/github_hartzell_freebsd-ports/audio %
```

Interestingly, adding `PORTREVISION= 1` to my copy of the port gives a
shorter version of the same error message:

```
hartzell at corvid:/usr/portshaker/github_hartzell_freebsd-ports/audio % sudo portshaker -M
make: "/usr/share/mk/bsd.port.mk" line 32: Cannot open /usr/ports/Mk/bsd.port.mk
make: "/usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver/Makefile" line 88: Malformed conditional (${ARCH} == "i386")
make: "/usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver/Makefile" line 95: Malformed conditional (${ARCH} == "amd64")
make: "/usr/share/mk/bsd.port.mk" line 32: Cannot open /usr/ports/Mk/bsd.port.mk
make: Fatal errors encountered -- cannot continue[: make: stopped in /usr/portshaker/github_hartzell_freebsd-ports/audio/logitechmediaserver: bad number
hartzell at corvid:/usr/portshaker/github_hartzell_freebsd-ports/audio %
```

Everything works fine if I rename my customized port to
e.g. `gh-logitechmusicserver`, but I thought that one of the goals of
portshaker was to override local ports.

I can live with just giving my port a custom name, but I'd like to
understand where my disconnect is (am I doing it wrong, or
misunderstanding something, or ...).

Thanks for any insights,

g.

[1]: https://github.com/hartzell/freebsd-ports
[2]: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=235468
[3]: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=2403971