Cube build segmentation fault if nspax is too small

[stscijirahub]

Issue JP-4351 was created on JIRA by David Law:

I ran into an unusual cube building crash when certain custom parameters are used.

Taking the cal file https://stsci.box.com/s/fywj4ye0i7kuojq3t1lin254ne2v5hkn as an example, the following command works fine:

strun cube_build jw03399001001_03106_00002_nrs1_cal.fits --wavemin=2.87 --wavemax=3.86 --scalexy=0.05 --ra_center=269.30521548 --dec_center=67.06128098 --nspax_x=100 --nspax_y=100

while this command with slightly lower nspax_x and nspax_y does not:

strun cube_build jw03399001001_03106_00002_nrs1_cal.fits --wavemin=2.87 --wavemax=3.86 --scalexy=0.05 --ra_center=269.30521548 --dec_center=67.06128098 --nspax_x=80 --nspax_y=80

This latter case gives a segmentation fault and leaked semaphore object warnings.