Match-error for patches

[Andreas Enge <andreas@enge.fr>]

Hello,

something very curious is right now (git 561fb6c) happening.

$ make install
$ ./pre-inst-env guix build --no-substitutes -n soprano
The following derivation would be built:
   /gnu/store/f0j3r6h2q4j449y64wz6759acdjgpz7j-soprano-2.9.4.drv
$ guix build --no-substitutes -n soprano
Backtrace:
In ice-9/boot-9.scm:
 149: 19 [catch system-error ...]
 157: 18 [#<procedure 2e4fc80 ()>]
In guix/scripts/build.scm:
 426: 17 [#<procedure 2ee13a0 at guix/scripts/build.scm:422:2 ()>]
 318: 16 [options->derivations #<build-daemon 256.14 2e51f00> (# # # # ...)]
In srfi/srfi-1.scm:
 664: 15 [filter-map #<procedure 41641c0 at guix/scripts/build.scm:318:18 (expr)> #]
In guix/packages.scm:
 600: 14 [cache # # #<procedure thunk ()>]
 849: 13 [thunk]
 781: 12 [bag->derivation # # #]
In srfi/srfi-1.scm:
 576: 11 [map #<procedure 3b421e0 at guix/packages.scm:783:30 (t-10633)> (# # # ...)]
In guix/packages.scm:
 642: 10 [expand-input # # # ...]
 600: 9 [cache # # #<procedure thunk ()>]
 849: 8 [thunk]
 781: 7 [bag->derivation # # #]
In srfi/srfi-1.scm:
 576: 6 [map #<procedure 4c5a780 at guix/packages.scm:783:30 (t-10633)> (# # # ...)]
In guix/packages.scm:
 657: 5 [expand-input # # # ...]
In guix/store.scm:
 920: 4 [run-with-store # ...]
 871: 3 [#<procedure 4ce9b10 at guix/store.scm:870:6 (store)> #]
In guix/packages.scm:
 389: 2 [patch-and-repack # # # ...]
In srfi/srfi-1.scm:
 601: 1 [map #<procedure 4ce9ae0 at guix/packages.scm:389:9 (number patch)> # #]
In guix/packages.scm:
 391: 0 [#<procedure 4ce9ae0 at guix/packages.scm:389:9 (number patch)> 1 #f]

guix/packages.scm:391:17: In procedure #<procedure 4ce9ae0 at guix/packages.scm:389:9 (number patch)>:
guix/packages.scm:391:17: Throw to key `match-error' with args `("match" "no matching pattern")'.

What could this mean? It is probably related to the fact that soprano
requires a patch. But howw is it possible to have different behaviour between
the installed version or with the ./pre-inst-env command?

Moreover, a local build of soprano fails with
CMake Error at cmake/modules/FindQt4.cmake:1239 (MESSAGE):
  Qt qmake not found!
Call Stack (most recent call first):
  CMakeLists.txt:46 (find_package)
whereas the package has been built on hydra in the meantime.

Andreas