Bootstrapping alex

[Colin Watson <cjwatson@debian.org>]

Folks on #debian-buildd are rediscovering some of the difficulties at
the tail end of the ghc bootstrap process for arm64 and ppc64el that I
discovered when doing this for Ubuntu a few months back.  I filed
https://github.com/simonmar/happy/issues/29 to see if happy can be
improved, but for alex, what do people think of this approach to
eliminate its build-dependency loop?  I've test-built it and it works
fine, but it does introduce the new constraint described in the
changelog.

diff -rN -u old-debian/changelog new-debian/changelog
--- old-debian/changelog	2014-08-30 11:39:47.995389361 -0700
+++ new-debian/changelog	2014-08-30 11:39:48.003389362 -0700
@@ -1,3 +1,12 @@
+alex (3.1.3-2) UNRELEASED; urgency=medium
+
+  * Configure using --with-alex=/bin/true and drop the
+    self-build-dependency, to make bootstrapping easier.  Requires any
+    future patches to *.x to include corresponding patches to the generated
+    files.
+
+ -- Colin Watson <cjwatson@debian.org>  Sat, 30 Aug 2014 11:13:22 -0700
+
 alex (3.1.3-1) unstable; urgency=low
 
   * Adjust watch file to new hackage layout
diff -rN -u old-debian/control new-debian/control
--- old-debian/control	2014-08-30 11:39:47.999389362 -0700
+++ new-debian/control	2014-08-30 11:39:48.003389362 -0700
@@ -9,7 +9,6 @@
                haskell-devscripts (>= 0.8.19),
                debhelper (>= 9),
                ghc,
-               alex,
                happy,
                jade,
                docbook-utils,
diff -rN -u old-debian/rules new-debian/rules
--- old-debian/rules	2014-08-30 11:39:47.999389362 -0700
+++ new-debian/rules	2014-08-30 11:39:48.003389362 -0700
@@ -9,6 +9,8 @@
 
 DEB_BUILD_DEPENDENCIES = build-arch
 
+DEB_SETUP_GHC_CONFIGURE_ARGS := --with-alex=/bin/true
+
 DEB_ENABLE_TESTS = yes
 
 include /usr/share/cdbs/1/rules/debhelper.mk

Thanks,

-- 
Colin Watson                                       [cjwatson@debian.org]