build: Change default for -Dman-pages from disabled to auto

Previously, `-Dman=false` was the default, because the generated man
pages were shipped in the distribution tarball already, so the option
actually mostly controlled whether to *re*build them.

The generated pages are no longer shipped in the tarball (and probably
haven’t been since the port to Meson, though I haven’t checked), so it
makes sense to change the default to encourage building the man pages if
the right tooling (`rst2man`) is available.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

.gitlab-ci.yml

@@ -11,7 +11,7 @@ cache:
     - _ccache/
 
 variables:
-  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/glib/fedora:v25"
+  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/glib/fedora:v26"
   COVERITY_IMAGE: "registry.gitlab.gnome.org/gnome/glib/coverity:v7"
   DEBIAN_IMAGE: "registry.gitlab.gnome.org/gnome/glib/debian-stable:v19"
   ALPINE_IMAGE: "registry.gitlab.gnome.org/gnome/glib/alpine:v3"

.gitlab-ci/fedora.Dockerfile

@@ -49,6 +49,7 @@ RUN dnf -y update \
     ninja-build \
     pcre2-devel \
     "python3-dbusmock >= 0.18.3-2" \
+    python3-docutils \
     python3-packaging \
     python3-pip \
     python3-pygments \

meson_options.txt

@@ -45,7 +45,7 @@ option('man',
 
 option('man-pages',
        type : 'feature',
-       value : 'disabled',
+       value : 'auto',
        description : 'generate man pages (requires rst2man)',
        deprecated : { 'true': 'enabled', 'false': 'disabled' })