Conflict with udp-conduit CSPAWN default

[Paul Hargrove]

When configuring GASNet's udp-conduit it is possible to pass --with-gasnet-cspawn-cmd=... (or set GASNET_CSPAWN_CMD in ones environment) to change the default value for GASNET_SPAWNFN to C, rather than S.

With GASNet configured in this manner, amudprun would normally launch using the value given at configure time, with no need to set env vars at runtime. However, currently upcxx-run takes the absence of a GASNET_SPAWNFN as a license to set GASNET_SPAWNFN=S, thus defeating the configure-time default setting.

Clearly, GASNET_SPAWNFN=C is a work around.
However, I suspect (but haven't the time to try) that simply leaving GASNET_SPAWNFN unset is a reasonable solution.

[Dan Bonachea]

Removing version: mk-develop branch (automated comment)