MAINT: PR 12038 revisions

* split up pip install commands when `PRE_WHEELS` may
be involved

.travis.yml

@@ -21,6 +21,7 @@ env:
    - PRE_WHEELS="https://pypi.anaconda.org/scipy-wheels-nightly/simple"
    # Using a single thread can actually speed up some computations on Travis
    - OPENBLAS_NUM_THREADS=1
+   - OTHERSPEC=""
 
 matrix:
   include:
@@ -56,6 +57,7 @@ matrix:
         - TESTMODE=fast
         - COVERAGE=
         - NUMPYSPEC="--pre --upgrade --timeout=60 -i $PRE_WHEELS numpy"
+        - OTHERSPEC="--pre --upgrade --timeout=60"
         # Need a test with most recent Python version where we build from an
         # sdist (uses pip build isolation), to check that the version we
         # specify in pyproject.toml (will be older than --pre --upgrade) works
@@ -87,6 +89,7 @@ matrix:
       env:
         - TESTMODE=full
         - NUMPYSPEC="--pre --upgrade --timeout=60 -i $PRE_WHEELS numpy"
+        - OTHERSPEC="--pre --upgrade --timeout=60"
         - NPY_USE_BLAS_ILP64=1
     - python: 3.6
       if: type = pull_request
@@ -166,7 +169,8 @@ before_install:
   # Miniforge / conda-forge), so skip arm64 here
   - |
     if [[ "$TRAVIS_CPU_ARCH" != "arm64" ]]; then
-         travis_retry pip install --upgrade pip setuptools wheel $NUMPYSPEC cython pytest pytest-xdist mpmath argparse Pillow codecov gmpy2 pybind11
+         travis_retry pip install --upgrade pip setuptools wheel $OTHERSPEC cython pytest pytest-xdist mpmath argparse Pillow codecov gmpy2 pybind11
+         travis_retry pip install --upgrade $NUMPYSPEC
     fi
   - |
     if [ -n "${USE_DEBUG}" ]; then