Add setuptools>=38 as a build_dep.

conda_requirements.txt

@@ -1,14 +1,15 @@
 # The requirements packages that can be installed with
 #    conda install -y -c conda-forge --file conda_requirements.txt
-numpy >= 1.13
-future >= 0.15
-astropy >= 2.0
-pybind11 >= 2.2
-pip >= 9.0
-gcc >= 4.8
-fftw >= 3.3
-eigen >= 3.3
+setuptools>=38
+numpy>=1.13
+future>=0.15
+astropy>=2.0
+pybind11>=2.2
+pip>=9.0
+gcc>=4.8
+fftw>=3.3
+eigen>=3.3
 
 # Not technically required, but useful.
-pyyaml >= 3.12
-pandas >= 0.20
+pyyaml>=3.12
+pandas>=0.20

pyproject.toml

@@ -0,0 +1,2 @@
+[build-system]
+requires = ["setuptools>=38", "pybind11>=2.2"]

requirements.txt

@@ -4,17 +4,18 @@
 # These are in conda_requirements.txt.  If using that, you may prefer to do
 #   conda install -c conda-forge --file conda_requirements.txt
 # prior to running pip install -r requirements.txt
-eigency >= 1.77
-numpy >= 1.13
-future >= 0.15
-astropy >= 2.0
-pybind11 >= 2.2
-pip >= 9.0
+setuptools>=38
+eigency>=1.77
+numpy>=1.13
+future>=0.15
+astropy>=2.0
+pybind11>=2.2
+pip>=9.0
 
 # Not technically required, but useful.
-pyyaml >= 3.12
-pandas >= 0.20
+pyyaml>=3.12
+pandas>=0.20
 
 # This is not in conda.  Let pip install these.
-LSSTDESC.Coord >= 1.0.5
-starlink-pyast >= 3.9.0  # Also not required, but useful.
+LSSTDESC.Coord>=1.0.5
+starlink-pyast>=3.9.0  # Also not required, but useful.

setup.py

@@ -4,15 +4,24 @@
 import ctypes
 import types
 
-from setuptools import setup, Extension, find_packages
-from setuptools.command.build_ext import build_ext
-from setuptools.command.build_clib import build_clib
-from setuptools.command.install import install
-from setuptools.command.install_scripts import install_scripts
-from setuptools.command.easy_install import easy_install
-from setuptools.command.test import test
-import setuptools
-print("Using setuptools version",setuptools.__version__)
+try:
+    from setuptools import setup, Extension, find_packages
+    from setuptools.command.build_ext import build_ext
+    from setuptools.command.build_clib import build_clib
+    from setuptools.command.install import install
+    from setuptools.command.install_scripts import install_scripts
+    from setuptools.command.easy_install import easy_install
+    from setuptools.command.test import test
+    import setuptools
+    print("Using setuptools version",setuptools.__version__)
+except ImportError:
+    print()
+    print("****")
+    print("    Installation requires setuptools version >= 38.")
+    print("    Please upgrade or install with pip install -U setuptools")
+    print("****")
+    print()
+    raise
 
 print('Python version = ',sys.version)
 py_version = "%d.%d"%sys.version_info[0:2]  # we check things based on the major.minor version.
@@ -403,6 +412,7 @@ def add_dirs(builder, output=False):
     # Finally, add pybind11's include dir
     import pybind11
     print('PyBind11 is version ',pybind11.__version__)
+    #print(pybind11.__file__)
     # Include both the standard location and the --user location, since it's hard to tell
     # which one is the right choice.
     builder.include_dirs.append(pybind11.get_include(user=True))
@@ -594,7 +604,7 @@ def run_tests(self):
               py_sources,
               undef_macros = undef_macros)
 
-build_dep = ['pybind11>=2.2']
+build_dep = ['setuptools>=38', 'pybind11>=2.2']
 run_dep = ['numpy', 'future', 'astropy', 'LSSTDESC.Coord']
 test_dep = ['pytest', 'pytest-xdist', 'pytest-timeout', 'scipy']
 
@@ -672,7 +682,7 @@ def run_tests(self):
     libraries=[lib],
     ext_modules=[ext],
     setup_requires=build_dep,
-    install_requires=run_dep,
+    install_requires=build_dep + run_dep,
     tests_require=test_dep,
     cmdclass = {'build_ext': my_build_ext,
                 'build_clib': my_build_clib,