gh-90539: doc: Expand on what should not go into CFLAGS, LDFLAGS (GH-…

…92754) (cherry picked from commit 61f24e7) Co-authored-by: Matthias Köppe <[email protected]>
python · Jun 20, 2022 · 2454dbe · 2454dbe
1 parent 9d73adf
commit 2454dbe
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/Doc/using/configure.rst b/Doc/using/configure.rst
@@ -652,6 +652,17 @@ Compiler flags
    extensions.  Use it when a compiler flag should *not* be part of the
    distutils :envvar:`CFLAGS` once Python is installed (:issue:`21121`).
 
+   In particular, :envvar:`CFLAGS` should not contain:
+
+   * the compiler flag `-I` (for setting the search path for include files).
+     The `-I` flags are processed from left to right, and any flags in
+     :envvar:`CFLAGS` would take precedence over user- and package-supplied `-I`
+     flags.
+
+   * hardening flags such as `-Werror` because distributions cannot control
+     whether packages installed by users conform to such heightened
+     standards.
+
    .. versionadded:: 3.5
 
 .. envvar:: EXTRA_CFLAGS
@@ -764,6 +775,13 @@ Linker flags
    :envvar:`CFLAGS_NODIST`.  Use it when a linker flag should *not* be part of
    the distutils :envvar:`LDFLAGS` once Python is installed (:issue:`35257`).
 
+   In particular, :envvar:`LDFLAGS` should not contain:
+
+   * the compiler flag `-L` (for setting the search path for libraries).
+     The `-L` flags are processed from left to right, and any flags in
+     :envvar:`LDFLAGS` would take precedence over user- and package-supplied `-L`
+     flags.
+
 .. envvar:: CONFIGURE_LDFLAGS_NODIST
 
    Value of :envvar:`LDFLAGS_NODIST` variable passed to the ``./configure``