I noticed with some surprise the following sequence:
$ cabal --version
cabal-install version 1.16.0.2
using version 1.16.0.3 of the Cabal library
$ cabal clean
$ cabal install
$ cat dist/build/autogen/cabal_macros.h | grep VERSION_Cabal
#define VERSION_Cabal "1.17.0"
Alright, so that, in retrospect, makes sense. The version is which *my* library is linked with is the relevant one, not the one cabal-install was linked with [1].
So the natural next thought is to move the MIN_VERSION_Cabal test into Setup.hs, and force cabal to use it by setting the build type to Custom. But... I just learned from this ticket that the cabal macros are not available in Setup.hs:
Uh oh, what's left?
-Ryan
[1] P.S. Personally I'm now using a bash function like below, to force the two versions to be the same:
function safe_cabal_install () {
VER=`cabal --version | tail -n1 | awk '{ print $3 }'`
cabal install --constraint="Cabal==$VER" $*
}