merge_obs use stack for PSF merge infile

[kglotfelty]

I hit an error when combining 45 observations because the infile parameter to dmimgfilt is longer than 2048 characters

  Combining 45 observations.
  Input string is longer than 2048 char: parameter argument error : infile
  # merge_obs (05 November 2021): ERROR Unable to run dmimgfilt with arguments: infile=...2070 characters....

I don't know if the error message is new or just first time hitting it. Looking at the code, I think

ciao-contrib/ciao_contrib/_tools/merging.py

Line 2873 in be347ee

args = ["infile={}".format(','.join(psfmap_files)),

can be updated to replace the long infile with a temporary stack and then it should be able to handle it.

Kenny

[kglotfelty]

Do we have a context manager for things like this

with TemporaryStack(<some iterable>) as my_stack:
    infile=f"@-{my_stack}"
    run()

[DougBurke]

I'm pretty sure we don't (yet) have such a context manager.