add notes on versions

.github/workflows/python-package.yml

@@ -18,9 +18,9 @@ jobs:
             matrix:
                 os: [ubuntu-22.04]
                 python-version: ['3.10']
-                astropy-version: ['<6.1']
+                astropy-version: ['<6.1']  # Compatilbilty with desiconda 20240425-2.2.0.
                 fitsio-version: ['==1.2.1', '<2']
-                numpy-version: ['<1.23']
+                numpy-version: ['<1.23']  # Compatilbilty with desiconda 20240425-2.2.0.
         env:
             DESIUTIL_VERSION: 3.4.3
             # DESIMODEL: ${GITHUB_WORKSPACE}/desimodel
@@ -73,9 +73,9 @@ jobs:
             matrix:
                 os: [ubuntu-22.04]
                 python-version: ['3.10']
-                astropy-version: ['<6.1']
+                astropy-version: ['<6.1']  # Compatilbilty with desiconda 20240425-2.2.0.
                 fitsio-version: ['<2']
-                numpy-version: ['<1.23']  # to keep asscalar, used by astropy
+                numpy-version: ['<1.23']  # Compatilbilty with desiconda 20240425-2.2.0.
         env:
             DESIUTIL_VERSION: 3.4.3
             # DESIMODEL: ${GITHUB_WORKSPACE}/desimodel

requirements.txt

@@ -1,13 +1,19 @@
-# numpy<1.20
 pytz
 requests
+# Ensure scipy dependency does not bring in a recent version of numpy.
 scipy<1.9
+# The version of astropy will be reset by GitHub Actions tests.
 astropy
+# Ensure compatibility with numpy <1.23.
 numba<0.60
+# Ensure compatibility with numpy <1.23.
 matplotlib<3.9
 healpy
+# It is becoming difficult to install speclite and specsim directly from
+# git+https, so installing from PyPI is definitely preferred here.
 speclite
 specsim
+# The version of fitsio will be reset by GitHub Actions tests.
 fitsio
 # Install desiutil separately since it is needed for the other installs.
 # git+https://github.com/desihub/[email protected]#egg=desiutil