I install python3 with Linuxbrew. All header files have been symlinked to "~/.linuxbrew/inlcude". It raises warnings when I building with custom CPPFLAGS.

```
checking curses.h usability... no
checking curses.h presence... yes
configure: WARNING: curses.h: present but cannot be compiled
configure: WARNING: curses.h:     check for missing prerequisite headers?
configure: WARNING: curses.h: see the Autoconf documentation
configure: WARNING: curses.h:     section "Present But Cannot Be Compiled"
configure: WARNING: curses.h: proceeding with the compiler's result
configure: WARNING:     ## --------------------------------------- ##
configure: WARNING:     ## Report this to https://bugs.python.org/ ##
configure: WARNING:     ## --------------------------------------- ##
checking for curses.h... no
checking ncurses.h usability... no
checking ncurses.h presence... yes
configure: WARNING: ncurses.h: present but cannot be compiled
configure: WARNING: ncurses.h:     check for missing prerequisite headers?
configure: WARNING: ncurses.h: see the Autoconf documentation
configure: WARNING: ncurses.h:     section "Present But Cannot Be Compiled"
configure: WARNING: ncurses.h: proceeding with the compiler's result
configure: WARNING:     ## --------------------------------------- ##
configure: WARNING:     ## Report this to https://bugs.python.org/ ##
configure: WARNING:     ## --------------------------------------- ##
checking for ncurses.h... no
checking for term.h... yes
```

See https://github.com/Homebrew/linuxbrew-core/pull/22307 for more details.