gstpluginloader: show the reason when spawning of gst-plugin-scanner fail
This fix helps in cross compiling when the meson tests runs using a qemu wrapper.
Log before:
0:00:00.134433682 3931 0x4000014400 LOG GST_PLUGIN_LOADING gstpluginloader.c:474:gst_plugin_loader_spawn: Trying GST_PLUGIN_SCANNER env var: /build/tmp/work/core2-64-poky-linux/gstreamer1.0/1.18.5-r0/build/libs/gst/helpers/gst-plugin-scanner
0:00:00.134468135 3931 0x4000014400 LOG GST_PLUGIN_LOADING gstpluginloader.c:432:gst_plugin_loader_try_helper: Trying to spawn gst-plugin-scanner helper at /build/tmp/work/core2-64-poky-linux/gstreamer1.0/1.18.5-r0/build/libs/gst/helpers/gst-plugin-scanner
0:00:00.137844876 3931 0x4000014400 INFO GST_PLUGIN_LOADING gstpluginloader.c:502:gst_plugin_loader_spawn: No gst-plugin-scanner available, or not working
Log after:
0:00:00.114916369 151 0x4000014400 LOG GST_PLUGIN_LOADING gstpluginloader.c:480:gst_plugin_loader_spawn: Trying GST_PLUGIN_SCANNER env var: /build/tmp/work/core2-64-poky-linux/gstreamer1.0/1.18.5-r0/build/libs/gst/helpers/gst-plugin-scanner
0:00:00.114948417 151 0x4000014400 LOG GST_PLUGIN_LOADING gstpluginloader.c:433:gst_plugin_loader_try_helper: Trying to spawn gst-plugin-scanner helper at /build/tmp/work/core2-64-poky-linux/gstreamer1.0/1.18.5-r0/build/libs/gst/helpers/gst-plugin-scanner
0:00:00.117880951 151 0x4000014400 ERROR GST_PLUGIN_LOADING gstpluginloader.c:442:gst_plugin_loader_try_helper: Spawning gst-plugin-scanner helper failed: Failed to execute child process “/build/tmp/work/core2-64-poky-linux/gstreamer1.0/1.18.5-r0/build/libs/gst/helpers/gst-plugin-scanner” (No such file or directory)
0:00:00.117925017 151 0x4000014400 INFO GST_PLUGIN_LOADING gstpluginloader.c:508:gst_plugin_loader_spawn: No gst-plugin-scanner available, or not working
Edited by Jose Quaresma