doc: Cross-reference virtual build machines from ‘guix time-machine’.

* doc/guix.texi (Invoking guix time-machine): Tweak the note about
packages that may fail to build.  Add cross-reference to virtual build
machines.

Change-Id: Ib2a4a28cdca0c8970d0f5327e39b4a21800ea2e1

1 files changed, 4 insertions, 4 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index e8db900d1f..6a3b85d54a 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -5029,10 +5029,10 @@ Although it should technically be possible to travel to such an old
 commit, the ease to do so will largely depend on the availability of
 binary substitutes.  When traveling to a distant past, some packages may
 not easily build from source anymore.  One such example are old versions
-of Python 2 which had time bombs in its test suite, in the form of
-expiring SSL certificates.  This particular problem can be worked around
-by setting the hardware clock to a value in the past before attempting
-the build.
+of OpenSSL whose tests would fail after a certain date.  This particular
+problem can be worked around by running a @dfn{virtual build machine}
+with its clock set to the right time (@pxref{build-vm, Virtual Build
+Machines}).
 @end quotation
 
 The general syntax is: