package/libcamera: improve future reproducibility by forcing auto features to disabled

meson allows to force all features set to "auto" to default to disabled
except if explicitly enabled via the auto_features argument, c.f.
https://mesonbuild.com/Build-options.html#features

"""
If the value of a feature option is set to auto, that value is
overridden by the global auto_features option (which defaults to auto).
This is intended to be used by packagers who want to have full control
on which dependencies are required and which are disabled, and not rely
on build-deps being installed (at the right version) to get a feature
enabled.
"""

The only auto feature that we hadn't disabled explicitly is the
gstreamer plugin. It is however expected that this wasn't a mistake as
the dependencies for the gstreamer pluging wouldn't have been met
thanks to the explicit LIBCAMERA_DEPENDENCIES we have based on the
presence of the gstreamer symbols in the global config.

This should make it less likely for future releases of libcamera to
regress in terms of reproducibility because of "auto" features (though
changes from "auto" to "enabled" wouldn't be caught and would be
susceptible to race conditions with their dependencies in case they
aren't properly specified and built after libcamera is).

Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libcamera/libcamera.mk

@@ -16,9 +16,9 @@ LIBCAMERA_DEPENDENCIES = \
 	libyaml \
 	gnutls
 LIBCAMERA_CONF_OPTS = \
+	-Dauto_features=disabled \
 	-Dandroid=disabled \
 	-Ddocumentation=disabled \
-	-Dqcam=disabled \
 	-Dtest=false \
 	-Dwerror=false
 LIBCAMERA_INSTALL_STAGING = YES
@@ -48,8 +48,6 @@ endif
 ifeq ($(BR2_PACKAGE_LIBCAMERA_PYTHON),y)
 LIBCAMERA_DEPENDENCIES += python3 python-pybind
 LIBCAMERA_CONF_OPTS += -Dpycamera=enabled
-else
-LIBCAMERA_CONF_OPTS += -Dpycamera=disabled
 endif
 
 ifeq ($(BR2_PACKAGE_LIBCAMERA_V4L2),y)
@@ -71,8 +69,6 @@ LIBCAMERA_CONF_OPTS += -Dpipelines=$(subst $(space),$(comma),$(LIBCAMERA_PIPELIN
 ifeq ($(BR2_PACKAGE_LIBCAMERA_COMPLIANCE),y)
 LIBCAMERA_DEPENDENCIES += gtest libevent
 LIBCAMERA_CONF_OPTS += -Dlc-compliance=enabled
-else
-LIBCAMERA_CONF_OPTS += -Dlc-compliance=disabled
 endif
 
 # gstreamer-video-1.0, gstreamer-allocators-1.0
@@ -84,8 +80,6 @@ endif
 ifeq ($(BR2_PACKAGE_LIBEVENT),y)
 LIBCAMERA_CONF_OPTS += -Dcam=enabled
 LIBCAMERA_DEPENDENCIES += libevent
-else
-LIBCAMERA_CONF_OPTS += -Dcam=disabled
 endif
 
 ifeq ($(BR2_PACKAGE_TIFF),y)
@@ -95,15 +89,11 @@ endif
 ifeq ($(BR2_PACKAGE_HAS_UDEV),y)
 LIBCAMERA_CONF_OPTS += -Dudev=enabled
 LIBCAMERA_DEPENDENCIES += udev
-else
-LIBCAMERA_CONF_OPTS += -Dudev=disabled
 endif
 
 ifeq ($(BR2_PACKAGE_LTTNG_LIBUST),y)
 LIBCAMERA_CONF_OPTS += -Dtracing=enabled
 LIBCAMERA_DEPENDENCIES += lttng-libust
-else
-LIBCAMERA_CONF_OPTS += -Dtracing=disabled
 endif
 
 ifeq ($(BR2_PACKAGE_LIBEXECINFO),y)