(alist-replace
                           'unpack
                           ;; FIXME: Remove this when gnu-build-system handles that
                           ;; case correctly.
                           (lambda* (#:key inputs source #:allow-other-keys)                                        
                             (mkdir "source")
                             (chdir "source")
                             (copy-recursively source ".")
                             (copy-recursively (assoc-ref %build-inputs "libpthread") ".")
                             #t)
                           %standard-phases))))))



`/nix/store/vk7fij36hdyyyx42yz7gj5vgi1n4l28l-git-checkout/CONFORMANCE' -> `./CONFORMANCE'
Backtrace:
In ice-9/boot-9.scm:
 157: 14 [catch #t #<catch-closure 2408d20> ...]
In unknown file:
   ?: 13 [apply-smob/1 #<catch-closure 2408d20>]
In ice-9/boot-9.scm:
  63: 12 [call-with-prompt prompt0 ...]
In ice-9/eval.scm:
 432: 11 [eval # #]
In ice-9/boot-9.scm:
2320: 10 [save-module-excursion #<procedure 2437bc0 at ice-9/boot-9.scm:3961:3 ()>]
3966: 9 [#<procedure 2437bc0 at ice-9/boot-9.scm:3961:3 ()>]
1645: 8 [%start-stack load-stack ...]
1650: 7 [#<procedure 243ddb0 ()>]
In unknown file:
   ?: 6 [primitive-load "/nix/store/x5f3m9304cydlg2sir71jyfkmpm59yjl-glibc-hurd-2.18-guile-builder"]
In ice-9/eval.scm:
 387: 5 [eval # ()]
In srfi/srfi-1.scm:
 830: 4 [every1 #<procedure 27995a0 at /nix/store/yjaqpxl2cwmymv001s1rs5z3pxi6h1vk-module-import/guix/build/gnu-build-system.scm:356:9 (expr)> ...]
In /nix/store/yjaqpxl2cwmymv001s1rs5z3pxi6h1vk-module-import/guix/build/gnu-build-system.scm:
 360: 3 [#<procedure 27995a0 at /nix/store/yjaqpxl2cwmymv001s1rs5z3pxi6h1vk-module-import/guix/build/gnu-build-system.scm:356:9 (expr)> #]
In ice-9/eval.scm:
 432: 2 [eval # #]
In ice-9/ftw.scm:
 481: 1 [loop "/nix/store/vk7fij36hdyyyx42yz7gj5vgi1n4l28l-git-checkout" "" ...]
In unknown file:
   ?: 0 [copy-file "/nix/store/vk7fij36hdyyyx42yz7gj5vgi1n4l28l-git-checkout/CONFORMANCE" ...]

ERROR: In procedure copy-file:
ERROR: In procedure copy-file: Permission denied
builder for `/nix/store/54a1n3hxq7x2kykz6x0i9q82bmj9zjjq-glibc-hurd-2.18.drv' failed with exit code 1