While final testing Distutils changes for Issue13590, I noticed that a few tests were failing unexpectedly on 2.7.x but passing on 3.2.x.  Upon further investigation, I discovered that in 2.7 there are two copies of "customize_compiler", the function being modified in Issue13590.  It appears that at one point prior to the decision to make no feature changes to Distutils, that customize_compiler was moved from distutils.sysconfig to distutils.ccompiler (fa69e891edf4).  Then, when the decision was made to revert changes and proceed with a new Distutils2/packaging, feature changes were reverted in 2.7 but, for unexplained reasons, only part of the changes were reverted (ad22bc22dddc).  Perhaps a clue is in the commit message:
  "reverting partially distutils to its 2.6.x state so 2.7a4 looks more
   like the 2.7b1 in this. the whole revert will occur after a4 is tagged "

From the change logs, I see no evidence that the whole revert ever happened.  This has left 2.7 Distutils with two virtually identical versions of customize_compiler with some commands and tests calling one and others calling the other.  (In 3.2.x, the only version is in distutils.sysconfig.)  They *were* virtually identically until Issue13590 changed one and missed the other.

Patch to follow which completes the revert for customize_compiler and brings 2.7.x and 3.2.2 back into sync with respect to this.  This patch is needed immediately for the upcoming 2.7.3 release.  I strongly urge a more complete audit for other discrepancies between the 2.7.x and 3.2.x versions of Distutils; this isn't the first time we've been burned recently by the effects of the reverts in 2.7.