diff --git a/gnu/packages/golang.scm b/gnu/packages/golang.scm
index 70cae6d87..7ed9cc750 100644
--- a/gnu/packages/golang.scm
+++ b/gnu/packages/golang.scm
@@ -199,11 +199,11 @@ garbage collection, various safety features and in the style of communicating
 sequential processes (CSP) concurrent programming features added.")
     (license license:bsd-3)))
 
-(define-public go-1.8
+(define-public go-1.9
   (package
     (inherit go-1.4)
     (name "go")
-    (version "1.8.3")
+    (version "1.9rc1")
     (source
      (origin
        (method url-fetch)
@@ -211,7 +211,7 @@ sequential processes (CSP) concurrent programming features added.")
                            name version ".src.tar.gz"))
        (sha256
         (base32
-         "19lzv4lqixj3v2gjaff0fdbbmgsq5r8lrfd61z2zvp778wjflpaz"))))
+         "0bj5dcvhz48bf6704qhqnybf220kgqgi93x4mx1n3k30xac7awc7"))))
     (arguments
      (substitute-keyword-arguments (package-arguments go-1.4)
        ((#:phases phases)
@@ -242,7 +242,7 @@ sequential processes (CSP) concurrent programming features added.")
                  ;; Add libgcc to runpath
                  (substitute* "cmd/link/internal/ld/lib.go"
                    (("!rpath.set") "true"))
-                 (substitute* "cmd/go/build.go"
+                 (substitute* "cmd/go/internal/work/build.go"
                    (("cgoldflags := \\[\\]string\\{\\}")
                     (string-append "cgoldflags := []string{"
                                    "\"-rpath=" gcclib "\""
@@ -265,7 +265,9 @@ sequential processes (CSP) concurrent programming features added.")
                      (substitute* file
                        ((regex all before test_name)
                         (string-append before "Disabled" test_name)))))
-                  '(("net/net_test.go" "(.+)(TestShutdownUnix.+)")
+                  '(;; See https://github.com/golang/go/commit/81ed9ca1d411f0bd8738ea60b3a8045446ad85fc
+                    ("cmd/go/go_test.go" "(.+)(TestExecutableGOROOT.+)")
+                    ("net/net_test.go" "(.+)(TestShutdownUnix.+)")
                     ("net/dial_test.go" "(.+)(TestDialTimeout.+)")
                     ("os/os_test.go" "(.+)(TestHostname.+)")
                     ("time/format_test.go" "(.+)(TestParseInSydney.+)")
@@ -366,4 +368,4 @@ sequential processes (CSP) concurrent programming features added.")
      `(("go" ,go-1.4)
        ,@(package-native-inputs go-1.4)))))
 
-(define-public go go-1.8)
+(define-public go go-1.9)
diff --git a/guix/build/graft.scm b/guix/build/graft.scm
index 16df169ec..83d797130 100644
--- a/guix/build/graft.scm
+++ b/guix/build/graft.scm
@@ -310,8 +310,7 @@ file name pairs."
   ;; Use 'exit-on-exception' to force an exit upon I/O errors, given that
   ;; 'n-par-for-each' silently swallows exceptions.
   ;; See <http://bugs.gnu.org/23581>.
-  (n-par-for-each (parallel-job-count)
-                  (exit-on-exception rewrite-leaf)
+  (for-each rewrite-leaf
                   (find-files directory (const #t)
                               #:directories? #t))
   (rename-matching-files output mapping))