gnu: guile-ssh: Add "guile3.0-ssh" variant.

* gnu/packages/ssh.scm (guile-ssh)[source]: Substitute 'GUILE_PKG'
stanza in "configure.ac".
* gnu/packages/ssh.scm (guile3.0-ssh): New variable.

gnu/packages/ssh.scm

@@ -65,6 +65,7 @@
   #:use-module (guix git-download)
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix packages)
+  #:use-module (guix utils)
   #:use-module (srfi srfi-1))
 
 (define-public libssh
@@ -257,6 +258,11 @@ Additionally, various channel-specific options can be negotiated.")
                   (substitute* "tests/server.scm"
                     (("= %libssh-minor-version 7")
                      ">= %libssh-minor-version 7"))
+
+                  ;; Allow builds with Guile 3.0.
+                  (substitute* "configure.ac"
+                    (("^GUILE_PKG.*$")
+                     "GUILE_PKG([3.0 2.2 2.0])\n"))
                   #t))))
     (build-system gnu-build-system)
     (outputs '("out" "debug"))
@@ -318,6 +324,39 @@ libssh library.")
     (inputs `(("guile" ,guile-2.0)
               ,@(alist-delete "guile" (package-inputs guile-ssh))))))
 
+(define-public guile3.0-ssh
+  (package
+    (inherit guile-ssh)
+    (name "guile3.0-ssh")
+    (arguments
+     (substitute-keyword-arguments (package-arguments guile-ssh)
+       ((#:phases phases)
+        `(modify-phases ,phases
+           (add-before 'bootstrap 'delete-old-guile-m4
+             (lambda _
+               ;; The old 'guile.m4' that's shipped would fail to recognize
+               ;; Guile 2.9 as "3.0".
+               (delete-file "m4/guile.m4")
+               #t))
+           (add-before 'build 'adjust-for-guile3
+             (lambda _
+               ;; Adjust for things that are deprecated in 2.2 and removed in
+               ;; 3.0.
+               (substitute* "tests/common.scm"
+                 (("define-module \\(tests common\\)")
+                  "define-module (tests common)
+  #:use-module (ice-9 threads)\n"))
+               (substitute* "modules/ssh/tunnel.scm"
+                 (("define-module \\(ssh tunnel\\)")
+                  "define-module (ssh tunnel)
+  #:use-module (ice-9 threads)"))
+               (substitute* "modules/srfi/srfi-64.upstream.scm"
+                 (("_IOLBF")
+                  "'line"))
+               #t))))))
+    (inputs `(("guile" ,guile-next)
+              ,@(alist-delete "guile" (package-inputs guile-ssh))))))
+
 (define-public corkscrew
   (package
     (name "corkscrew")