Compatibility Notices

As the Conda package ecosystem evolves and third-party software updates are released by Continuum and other providers, this may interfere with the stability of other codebases, such as STScI’s software. This page will proactively chronicle such events as they occur as well as provide workarounds to these issues.

If you spot a compatibility problem not listed here please let us know by sending an email to help[at]


You may be affected by an issue if you have updated your AstroConda environment on or after the dates listed in each section below.


NumPy v1.12.0 modified the way array slicing is handled and triggered a regression in the acstools and pysynphot packages:

  • acstools <= 2.0.6 - 2.0.7 released (Feb 16, 2017)
  • pysynphot <= - released (Feb 21, 2017)

One of the traceback messages to be aware of is as follows (traceback may be worded differently but usually complains about index not being an integer):

TypeError('slice indices must be integers or None or have an __index__ method',)

Recommended user actions:

  • Upgrade acstools to version 2.0.7 (i.e., conda update acstools)
  • Upgrade pysynphot to version (i.e., conda update pysynphot)

Alternative user action:

  • Downgrade numpy to version 1.11 (i.e., conda install numpy=1.11)


AstroPy v1.3 fully deprecated calls to The following packages are known to be incompatible with this release:

  • calcos <= 3.1.8 - Bugfix pending
  • costools <= 1.2.1 - Bugfix pending
  • fitsblender <= 0.2.6 - 0.3.0 released (Jan 17, 2017)

Recommended user actions:

  • Upgrade fitsblender to version 0.3.0 (i.e., conda update fitsblender)

Alternative user actions:

  • Downgrade astropy to version 1.2.1 (i.e., conda install astropy=1.2.1)


A list of known deprecation warnings detected in regression tests managed by STScI Science Software Branch is available here. This list is refreshed daily from “dev” and “public” test results.