gsch2pcb fails with "bad expression in eval" in m4

[Ben Gamari]

I've been working on a data acquisition board using the geda toolchain
exclusively and so far I have been quite pleased with the
results. Unfortunately, a few days ago gsch2pcb inexplicably stopped
working. In particular, it appears that m4 fails with the following,

  $ make pcb
  gsch2pcb -v project | tee pcb.log
  Loading schematic [/home/ben/lori/beagle-daq/beagle-daq.sch]
  Loading schematic [/home/ben/lori/beagle-daq/beagle-daq.sch]
  /usr/bin/m4:stdin:45: bad expression in eval: /2

If I kill the gsch2pcb process with Ctrl+\ I can see the command line
arguments of the failing process,

  /usr/bin/m4 -d -I/usr/share/pcb/m4 -I/usr/etc/pcb -I$HOME/.pcb -I. /usr/share/pcb/m4/common.m4 - >> beagle-daq.new.pcb

I have no idea what might have prompted this behavior and thankfully the
design is pretty much finished, but I would like to know what might be
wrong. I am using both gaf and pcb from git, although I have tested
versions back to 1.6.2 with no change in behavior. The project is
available through git at [1].

[1] git://goldnerlab.physics.umass.edu/beagle-daq

[Peter Clifton (pcjc2)]

This sounds like it could be the classic "-" in a footprint name bug.

Try "skip-m4" in your project file if you don't happen to use any of PCB's built in M4 footprints. (Even if you do - you may well find PCB can find everything it needs from the "newlib" export of PCB's generated M4 footprint library.