gnu: ghc: Use a LibFFI variant without static trampolines.

* gnu/packages/haskell.scm (ghc-7, ghc-8.0, ghc-8.4)[inputs]: Change from
LIBFFI to LIBFFI-SANS-STATIC-TRAMPOLINES.
* gnu/packages/libffi.scm (libffi-sans-static-trampolines): New variable.

gnu/packages/haskell.scm

@@ -423,7 +423,11 @@ libraries are included in this package.")
     (inputs
      `(("gmp" ,gmp)
        ("ncurses" ,ncurses)
-       ("libffi" ,libffi)
+
+       ;; Use a LibFFI variant without static trampolines to work around
+       ;; <https://gitlab.haskell.org/ghc/ghc/-/issues/20051>.
+       ("libffi" ,libffi-sans-static-trampolines)
+
        ("ghc-testsuite"
         ,(origin
            (method url-fetch)
@@ -597,7 +601,11 @@ interactive environment for the functional language Haskell.")
     (inputs
      `(("gmp" ,gmp)
        ("ncurses" ,ncurses)
-       ("libffi" ,libffi)
+
+       ;; Use a LibFFI variant without static trampolines to work around
+       ;; <https://gitlab.haskell.org/ghc/ghc/-/issues/20051>.
+       ("libffi" ,libffi-sans-static-trampolines)
+
        ("ghc-testsuite"
         ,(origin
            (method url-fetch)
@@ -696,7 +704,9 @@ interactive environment for the functional language Haskell.")
        (sha256
         (base32 "1ch4j2asg7pr52ai1hwzykxyj553wndg7wq93i47ql4fllspf48i"))))
     (inputs
-     (list gmp ncurses libffi))
+     ;; Note: GHC < 9 requires LibFFI < 3.4, or a variant without static
+     ;; trampolines.
+     (list gmp ncurses libffi-sans-static-trampolines))
     (native-inputs
      `(("perl" ,perl)
        ("python" ,python)               ; for tests

gnu/packages/libffi.scm

@@ -28,8 +28,10 @@
   #:use-module (gnu packages)
   #:use-module (guix licenses)
   #:use-module (guix packages)
+  #:use-module (guix gexp)
   #:use-module (guix download)
   #:use-module (guix git-download)
+  #:use-module (guix utils)
   #:use-module (gnu packages check)
   #:use-module (gnu packages pkg-config)
   #:use-module (gnu packages python)
@@ -78,6 +80,17 @@ conversions for values passed between the two languages.")
     ;; See <https://github.com/atgreen/libffi/blob/master/LICENSE>.
     (license expat)))
 
+;; Provide a variant without static trampolines as some packages
+;; (particularly GHC < 9) cannot handle them.  See
+;; <https://github.com/libffi/libffi/pull/647> for a discussion.
+(define-public libffi-sans-static-trampolines
+  (hidden-package
+   (package/inherit libffi
+     (arguments
+      (substitute-keyword-arguments (package-arguments libffi)
+        ((#:configure-flags flags #~'())
+         #~(append #$flags '("--disable-exec-static-tramp"))))))))
+
 (define-public python-cffi
   (package
     (name "python-cffi")