Deprecate support for Python 3.5 (by removing it from CI) (#31908)

* Deprecate support for Python 3.5 (by removing it from CI)

* Restore Python 3.9

6 files changed, 15 insertions, 9 deletions

diff --git a/.github/workflows/bootstrap.yml b/.github/workflows/bootstrap.yml
index 0522829303..9dd051d0ae 100644
--- a/.github/workflows/bootstrap.yml
+++ b/.github/workflows/bootstrap.yml
@@ -183,7 +183,7 @@ jobs:
     runs-on: ${{ matrix.macos-version }}
     strategy:
       matrix:
-        python-version: ['3.5', '3.6', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
         macos-version: ['macos-11', 'macos-12']
     if: github.repository == 'spack/spack'
     steps:
@@ -206,7 +206,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['2.7', '3.5', '3.6', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['2.7', '3.6', '3.7', '3.8', '3.9', '3.10']
     if: github.repository == 'spack/spack'
     steps:
       - name: Checkout
diff --git a/.github/workflows/unit_tests.yaml b/.github/workflows/unit_tests.yaml
index 44c00856f6..0a569d6d86 100644
--- a/.github/workflows/unit_tests.yaml
+++ b/.github/workflows/unit_tests.yaml
@@ -29,9 +29,9 @@ jobs:
         pip install --upgrade pip
         pip install --upgrade vermin
     - name: vermin (Spack's Core)
-      run: vermin --backport argparse --violations --backport typing -t=2.7- -t=3.5- -vvv lib/spack/spack/ lib/spack/llnl/ bin/
+      run: vermin --backport argparse --violations --backport typing -t=2.7- -t=3.6- -vvv lib/spack/spack/ lib/spack/llnl/ bin/
     - name: vermin (Repositories)
-      run: vermin --backport argparse --violations --backport typing -t=2.7- -t=3.5- -vvv var/spack/repos
+      run: vermin --backport argparse --violations --backport typing -t=2.7- -t=3.6- -vvv var/spack/repos
   # Run style checks on the files that have been changed
   style:
     runs-on: ubuntu-latest
@@ -101,7 +101,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['2.7', '3.5', '3.6', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['2.7', '3.6', '3.7', '3.8', '3.9', '3.10']
         concretizer: ['clingo']
         include:
         - python-version: 2.7
diff --git a/.github/workflows/windows_python.yml b/.github/workflows/windows_python.yml
index 37eb1082d9..e45fdb2bc8 100644
--- a/.github/workflows/windows_python.yml
+++ b/.github/workflows/windows_python.yml
@@ -31,9 +31,9 @@ jobs:
         python -m pip install --upgrade pip
         python -m pip install --upgrade vermin
     - name: vermin (Spack's Core)
-      run: vermin --backport argparse --backport typing -t='2.7-' -t='3.5-' -v spack/lib/spack/spack/ spack/lib/spack/llnl/ spack/bin/
+      run: vermin --backport argparse --backport typing -t='2.7-' -t='3.6-' -v spack/lib/spack/spack/ spack/lib/spack/llnl/ spack/bin/
     - name: vermin (Repositories)
-      run: vermin --backport argparse --backport typing -t='2.7-' -t='3.5-' -v spack/var/spack/repos
+      run: vermin --backport argparse --backport typing -t='2.7-' -t='3.6-' -v spack/var/spack/repos
   # Run style checks on the files that have been changed
   style:
     runs-on: windows-latest
diff --git a/lib/spack/docs/contribution_guide.rst b/lib/spack/docs/contribution_guide.rst
index 5c6cc325f5..837a850ff9 100644
--- a/lib/spack/docs/contribution_guide.rst
+++ b/lib/spack/docs/contribution_guide.rst
@@ -71,7 +71,7 @@ locally to speed up the review process.
    new release that is causing problems. If this is the case, please file an issue.
 
 
-We currently test against Python 2.7 and 3.5-3.9 on both macOS and Linux and
+We currently test against Python 2.7 and 3.6-3.10 on both macOS and Linux and
 perform 3 types of tests:
 
 .. _cmd-spack-unit-test:
diff --git a/lib/spack/docs/tables/system_prerequisites.csv b/lib/spack/docs/tables/system_prerequisites.csv
index 1841d4e28c..5f661883d3 100644
--- a/lib/spack/docs/tables/system_prerequisites.csv
+++ b/lib/spack/docs/tables/system_prerequisites.csv
@@ -1,5 +1,5 @@
 Name, Supported Versions, Notes, Requirement Reason
-Python, 2.7/3.5-3.10, , Interpreter for Spack
+Python, 2.7/3.6-3.10, , Interpreter for Spack
 C/C++ Compilers, , , Building software
 make, , , Build software
 patch, , , Build software
diff --git a/var/spack/repos/builtin/packages/spack/package.py b/var/spack/repos/builtin/packages/spack/package.py
index 5712cbad7a..645bda3387 100644
--- a/var/spack/repos/builtin/packages/spack/package.py
+++ b/var/spack/repos/builtin/packages/spack/package.py
@@ -21,6 +21,11 @@ class Spack(Package):
     maintainers = ["haampie"]
 
     version("develop", branch="develop")
+    version("0.18.1", sha256="d1491374ce280653ee0bc48cd80527d06860b886af8b0d4a7cf1d0a2309191b7")
+    version("0.18.0", sha256="7b8d1e6bb49cd4f46f79a93fa577e00336dafeb5452712e36efeafd02711d38e")
+    version("0.17.3", sha256="e9bf38917fa3b5231a65930aa657ef19fd380bebcc9ee44204167b1593f6fa06")
+    version("0.17.2", sha256="3c3c0eccc5c0a1fa89223cbdfd48c71c5be8b4645f5fa4e921426062a9b32d51")
+    version("0.17.1", sha256="96850f750c5a17675275aa059eabc2ae09b7a8c7b59c5762d571925b6897acfb")
     version("0.17.0", sha256="93df99256a892ceefb153d48e2080c01d18e58e27773da2c2a469063d67cb582")
     version("0.16.3", sha256="26636a2e2cc066184f12651ac6949f978fc041990dba73934960a4c9c1ea383d")
     version("0.16.2", sha256="ed3e5d479732b0ba82489435b4e0f9088571604e789f7ab9bc5ce89030793350")
@@ -32,6 +37,7 @@ class Spack(Package):
     # Python (with spack python -i ipython support)
     depends_on("python@2.6.0:2.7,3.5:", type="run")
     depends_on("python@2.7.0:2.7,3.5:", type="run", when="@0.18.0:")
+    depends_on("python@2.7.0:2.7,3.6:", type="run", when="@0.19.0:")
     depends_on("py-ipython", type="run")
 
     # Concretizer