NS->geni-lib converter should error if $PID or $EID is used in NS, or alternately, support them
I converted an NS file containing the following line:
tb-set-node-startcmd $imp \
{scp -p users.emulab.net:/proj/$PID/startcmds/$EID.sh /tmp && \
chmod +x /tmp/$EID.sh && \
/tmp/$EID.sh $MNT/$PID >& /tmp/$EID.log}
While this went through the converter, the result didn't work properly, because $PID and $EID are unavailable in the mechanism that runs start commands in GENI. (The $MNT is an Emulab opt
by the way, and there's a separate issue for that.)
A reasonable thing to do would be to look for uses of $EID and $PID (and other variables, too—see https://wiki.emulab.net/wiki/eventsystem) and fail the conversion if they appear in the command. Tell the user that "use of $BLAH is unsupported" for whatever BLAH they use.
It might be reasonable to error if the use of any envvar is detected.
An alternative would be to support those variables in some way, for start commands run in the GENI way.