[fractal/fractal-next] meson: Add option to skip `cargo-build` target

[Julian Sparber <jsparber src gnome org>]

commit 389bc11aec06666bc45bf4ea303215f6bd1c38d4
Author: Veli Tasali <veli tasali gmail com>
Date:   Tue May 4 15:52:10 2021 +0300

    meson: Add option to skip `cargo-build` target
    
    This is only needed when building docs or similar
    to avoid overhead.

 meson_options.txt | 4 ++++
 src/meson.build   | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/meson_options.txt b/meson_options.txt
index 35af6dbc..ea7fd89a 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -8,3 +8,7 @@ option(
   value: 'default',
   description: 'The build profile for Fractal. One of "default" or "development".'
 )
+option(
+  'skip-cargo-build', type: 'boolean', value: false,
+  description: 'Skip building "cargo-build" target.'
+)
diff --git a/src/meson.build b/src/meson.build
index 692a9999..c75e983f 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -52,7 +52,7 @@ sources = files(
 
 custom_target(
   'cargo-build',
-  build_by_default: true,
+  build_by_default: not get_option('skip-cargo-build'),
   input: sources,
   output: meson.project_name(),
   console: true,