現象

pip install pyodbcで以下のエラーでインストールできず.

zsh

$ pip install pyodbc
Collecting pyodbc
  Using cached pyodbc-4.0.32.tar.gz (280 kB)
  Preparing metadata (setup.py) ... done
Using legacy 'setup.py install' for pyodbc, since package 'wheel' is not installed.
Installing collected packages: pyodbc
  Running setup.py install for pyodbc ... error
  error: subprocess-exited-with-error
  
  × Running setup.py install for pyodbc did not run successfully.
  │ exit code: 1
  ╰─> [14 lines of output]
      running install
      running build
      running build_ext
      building 'pyodbc' extension
      creating build
      creating build/temp.macosx-12.3-x86_64-3.10
      creating build/temp.macosx-12.3-x86_64-3.10/src
      clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -DPYODBC_VERSION=4.0.32 -UMAC_OS_X_VERSION_10_7 -I/usr/local/include -I/Users/takasukaoru/python_project/corpdb/corpdb/.venv/include -I/Users/takasukaoru/.pyenv/versions/3.10.1/include/python3.10 -c src/buffer.cpp -o build/temp.macosx-12.3-x86_64-3.10/src/buffer.o -Wno-write-strings -Wno-deprecated-declarations
      In file included from src/buffer.cpp:12:
      src/pyodbc.h:56:10: fatal error: 'sql.h' file not found
      #include <sql.h>
               ^~~~~~~
      1 error generated.
      error: command '/usr/bin/clang' failed with exit code 1
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: legacy-install-failure

× Encountered error while trying to install package.
╰─> pyodbc

note: This is an issue with the package mentioned above, not pip.
hint: See above for output from the failure.

"sql.h"が見つかりません。sql.hとは・・・。

対処法

色々謎だったが、ここがヒットしたので、この対処法を試す.

zsh

brew install unixodbc

これで無事pip install pyodbcが通った.
理由は調査中.