Failed building wheel for http-parser | http_parser/parser.c:4:10: fatal error: Python.h: No such file or directory

Full log :
```
pip install git+https://github.com/benoitc/http-parser
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
Defaulting to user installation because normal site-packages is not writeable
Collecting git+https://github.com/benoitc/http-parser
Cloning https://github.com/benoitc/http-parser to /tmp/pip-req-build-ilQJuJ
Running command git clone -q https://github.com/benoitc/http-parser /tmp/pip-req-build-ilQJuJ
Installing build dependencies ... done
Getting requirements to build wheel ... done
Preparing wheel metadata ... done
Building wheels for collected packages: http-parser
Building wheel for http-parser (PEP 517) ... error
ERROR: Command errored out with exit status 1:
command: /usr/bin/python2 /usr/local/lib/python2.7/dist-packages/pip/_vendor/pep517/_in_process.py build_wheel /tmp/tmplnGbGj
cwd: /tmp/pip-req-build-ilQJuJ
Complete output (24 lines):
running bdist_wheel
running build
running build_py
creating build
creating build/lib.linux-x86_64-2.7
creating build/lib.linux-x86_64-2.7/http_parser
copying http_parser/_socketio.py -> build/lib.linux-x86_64-2.7/http_parser
copying http_parser/pyparser.py -> build/lib.linux-x86_64-2.7/http_parser
copying http_parser/util.py -> build/lib.linux-x86_64-2.7/http_parser
copying http_parser/__init__.py -> build/lib.linux-x86_64-2.7/http_parser
copying http_parser/http.py -> build/lib.linux-x86_64-2.7/http_parser
copying http_parser/reader.py -> build/lib.linux-x86_64-2.7/http_parser
running build_ext
make: Nothing to be done for 'all'.
building 'http_parser.parser' extension
creating build/temp.linux-x86_64-2.7
creating build/temp.linux-x86_64-2.7/http_parser
x86_64-linux-gnu-gcc -pthread -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-QDqKfA/python2.7-2.7.18=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -Iparser -I/usr/include/python2.7 -c http_parser/http_parser.c -o build/temp.linux-x86_64-2.7/http_parser/http_parser.o
x86_64-linux-gnu-gcc -pthread -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-QDqKfA/python2.7-2.7.18=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -Iparser -I/usr/include/python2.7 -c http_parser/parser.c -o build/temp.linux-x86_64-2.7/http_parser/parser.o
http_parser/parser.c:4:10: fatal error: Python.h: No such file or directory
4 | #include "Python.h"
| ^~~~~~~~~~
compilation terminated.
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
----------------------------------------
ERROR: Failed building wheel for http-parser
Failed to build http-parser
ERROR: Could not build wheels for http-parser which use PEP 517 and cannot be installed directly

```

示されている Python 2.7 環境で、報告された `pip install git+https://github.com/benoitc/http-parser` コマンドを再現します。まず `http_parser/parser.c` と記録された拡張機能のビルドコマンドから始め、次にパッケージのビルド設定を追跡します。報告された `Python.h` のコンパイル失敗なしに wheel がビルドできれば完了です。

索引モデルが issue の本文から書いたものです。