03/03: vm: Avoid needless file copy in 'load-in-linux-vm'.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit d2bcf35e1805b06fb575352531d9c439425dc379
Author: Ludovic Courtès <address@hidden>
Date:   Mon Nov 28 22:56:41 2016 +0100

    vm: Avoid needless file copy in 'load-in-linux-vm'.
    
    Reported by Chris Webber.
    
    * gnu/build/vm.scm (load-in-linux-vm)[image-file]: Remove.  Directly
    refer to OUTPUT instead.
---
 gnu/build/vm.scm |   16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/gnu/build/vm.scm b/gnu/build/vm.scm
index cc5cf45..60ee18e 100644
--- a/gnu/build/vm.scm
+++ b/gnu/build/vm.scm
@@ -79,12 +79,9 @@ it via /dev/hda.
 
 REFERENCES-GRAPHS can specify a list of reference-graph files as produced by
 the #:references-graphs parameter of 'derivation'."
-  (define image-file
-    (string-append "image." disk-image-format))
-
   (when make-disk-image?
     (unless (zero? (system* "qemu-img" "create" "-f" disk-image-format
-                            image-file
+                            output
                             (number->string disk-image-size)))
       (error "qemu-img failed")))
 
@@ -115,7 +112,7 @@ the #:references-graphs parameter of 'derivation'."
                                            builder)
                   (append
                    (if make-disk-image?
-                       `("-drive" ,(string-append "file=" image-file
+                       `("-drive" ,(string-append "file=" output
                                                   ",if=virtio"))
                        '())
                    ;; Only enable kvm if we see /dev/kvm exists.
@@ -126,11 +123,10 @@ the #:references-graphs parameter of 'derivation'."
                        '()))))
     (error "qemu failed" qemu))
 
-  (if make-disk-image?
-      (copy-file image-file output)
-      (begin
-        (mkdir output)
-        (copy-recursively "xchg" output))))
+  ;; When MAKE-DISK-IMAGE? is true, the image is in OUTPUT already.
+  (unless make-disk-image?
+    (mkdir output)
+    (copy-recursively "xchg" output)))
 
 
 ;;;