[PATCH v6 20/25] python: add devel package requirements to setuptools

[John Snow <jsnow@redhat.com>]

setuptools doesn't have a formal understanding of development requires,
but it has an optional feataures section. Fine; add a "devel" feature
and add the requirements to it.

To avoid duplication, we can modify pipenv to install qemu[devel]
instead. This enables us to run invocations like "pip install -e
.[devel]" and test the package on bleeding-edge packages beyond those
specified in Pipfile.lock.

Importantly, this also allows us to install the qemu development
packages in a non-networked mode: `pip3 install --no-index -e .[devel]`
will now fail if the proper development dependencies are not already
met. This can be useful for automated build scripts where fetching
network packages may be undesirable.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 python/Pipfile      |  5 +----
 python/Pipfile.lock | 14 +++++++++-----
 python/setup.cfg    |  9 +++++++++
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/python/Pipfile b/python/Pipfile
index fb23455eadd..e7acb8cefa4 100644
--- a/python/Pipfile
+++ b/python/Pipfile
@@ -4,10 +4,7 @@ url = "https://pypi.org/simple"
 verify_ssl = true
 
 [dev-packages]
-flake8 = ">=3.6.0"
-isort = ">=5.1.2"
-mypy = ">=0.770"
-pylint = ">=2.7.0"
+qemu = {editable = true, extras = ["devel"], path = "."}
 
 [packages]
 qemu = {editable = true,path = "."}
diff --git a/python/Pipfile.lock b/python/Pipfile.lock
index 5d3de43609d..18f3bba08f2 100644
--- a/python/Pipfile.lock
+++ b/python/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "986164b4c690953890066f288b48c3d84c63df86fc8fa30a26e9001d5b0968e0"
+            "sha256": "eff562a688ebc6f3ffe67494dbb804b883e2159ad81c4d55d96da9f7aec13e91"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -35,7 +35,7 @@
                 "sha256:12d05ab02614b6aee8df7c36b97d1a3b2372761222b19b58621355e82acddcff",
                 "sha256:78873e372b12b093da7b5e5ed302e8ad9e988b38b063b61ad937f26ca58fc5f0"
             ],
-            "index": "pypi",
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'",
             "version": "==3.9.0"
         },
         "importlib-metadata": {
@@ -51,7 +51,7 @@
                 "sha256:0a943902919f65c5684ac4e0154b1ad4fac6dcaa5d9f3426b732f1c8b5419be6",
                 "sha256:2bb1680aad211e3c9944dbce1d4ba09a989f04e238296c87fe2139faa26d655d"
             ],
-            "index": "pypi",
+            "markers": "python_version >= '3.6' and python_version < '4.0'",
             "version": "==5.8.0"
         },
         "lazy-object-proxy": {
@@ -114,7 +114,7 @@
                 "sha256:d65cc1df038ef55a99e617431f0553cd77763869eebdf9042403e16089fe746c",
                 "sha256:d7da2e1d5f558c37d6e8c1246f1aec1e7349e4913d8fb3cb289a35de573fe2eb"
             ],
-            "index": "pypi",
+            "markers": "python_version >= '3.5'",
             "version": "==0.812"
         },
         "mypy-extensions": {
@@ -145,9 +145,13 @@
                 "sha256:0e21d3b80b96740909d77206d741aa3ce0b06b41be375d92e1f3244a274c1f8a",
                 "sha256:d09b0b07ba06bcdff463958f53f23df25e740ecd81895f7d2699ec04bbd8dc3b"
             ],
-            "index": "pypi",
+            "markers": "python_version ~= '3.6'",
             "version": "==2.7.2"
         },
+        "qemu": {
+            "editable": true,
+            "path": "."
+        },
         "toml": {
             "hashes": [
                 "sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b",
diff --git a/python/setup.cfg b/python/setup.cfg
index 8a2c200a581..9d941386921 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -19,6 +19,15 @@ classifiers =
 python_requires = >= 3.6
 packages = find_namespace:
 
+[options.extras_require]
+# Run `pipenv lock` when changing these requirements.
+devel =
+    flake8 >= 3.6.0
+    isort >= 5.1.2
+    mypy >= 0.770
+    pylint >= 2.7.0
+
+
 [flake8]
 extend-ignore = E722  # Prefer pylint's bare-except checks to flake8's
 exclude = __pycache__,
-- 
2.30.2