01/12: services: qemu-binfmt: 'guix-support?' defaults to #t.

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit d4f5ea502d2c8358c2cf5fffd96cba0ac233984f
Author: Stefan <stefan-guix@vodafonemail.de>
AuthorDate: Thu Jan 7 21:44:22 2021 +0100

    services: qemu-binfmt: 'guix-support?' defaults to #t.
    
    * gnu/services/virtualization.scm (qemu-binfmt-service-type)[guix-support?]:
    Change the default from #f to #t.
    * doc/guix.texi (Transparent Emulation with QEMU): Change the default of
    ‘guix-support?’ from #f to #t.  Describe the implication of setting it to 
#f.
    
    Co-authored-by: Ludovic Courtès <ludo@gnu.org>
---
 doc/guix.texi                   | 6 +++++-
 gnu/services/virtualization.scm | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index cea7f8a..1234834 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -27338,7 +27338,7 @@ This is the configuration for the @code{qemu-binfmt} 
service.
 The list of emulated QEMU platforms.  Each item must be a @dfn{platform
 object} as returned by @code{lookup-qemu-platforms} (see below).
 
-@item @code{guix-support?} (default: @code{#f})
+@item @code{guix-support?} (default: @code{#t})
 When it is true, QEMU and all its dependencies are added to the build
 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
 @option{--chroot-directory} option}).  This allows the @code{binfmt_misc}
@@ -27367,6 +27367,10 @@ build}, transparently using QEMU to emulate the ARMv7 
CPU.  Pretty handy
 if you'd like to test a package build for an architecture you don't have
 access to!
 
+When @code{guix-support?} is set to @code{#f}, programs for other
+architectures can still be executed transparently, but invoking commands
+like @command{guix build -s armhf-linux @dots{}} will fail.
+
 @item @code{qemu} (default: @code{qemu})
 The QEMU package to use.
 @end table
diff --git a/gnu/services/virtualization.scm b/gnu/services/virtualization.scm
index f8d413d..a45da14 100644
--- a/gnu/services/virtualization.scm
+++ b/gnu/services/virtualization.scm
@@ -717,7 +717,7 @@ potential infinite waits blocking libvirt."))
   (platforms   qemu-binfmt-configuration-platforms
                (default '()))                     ;safest default
   (guix-support? qemu-binfmt-configuration-guix-support?
-                 (default #f)))
+                 (default #t)))
 
 (define (qemu-platform->binfmt qemu platform)
   "Return a gexp that evaluates to a binfmt string for PLATFORM, using the