PiBox

Autoconf-based apps are currently built outside the docker image used by the pibox dev build.
On Fedora, app builds were fine with just setting PKG_CONFIG_SYSROOT_DIR in the cross.sh build script.
On Debian 11 this is not sufficient. The following additional variables must be set when calling ./configure.

PKG_CONFIG_PATH="" 
PKG_CONFIG_LIBDIR=${STAGING_DIR}/usr/lib/pkgconfig:${STAGING_DIR}/usr/share/pkgconfig

See: https://autotools.io/pkgconfig/cross-compiling.html

All apps currently built for any mode by any metabuild (pibox and ironman) need to have this update.
The update should be applicable to other distros as well.

After reviewing all pkglist.* files for both pibox and ironman, the following app builds need to be reviewed
for use of cross.sh, and updated if found.

• appmgr
• bluez (not autoconf)
• ironman+gpio
• ironman+ironmancfg
• ironman+launcher
• ironman+monitor
• ironman+sensors
• ironman+www
• launcher
• lcdshow (not autoconf)
• libpibox
• mjpg-streamer (not autoconf)
• monkey (not autoconf)
• musicfe
• omxplayer (not autoconf)
• piboxd
• piboxwww (not autoconf)
• picam
• piclock
• pidialer
• pinet
• pipics
• pisentrycfg
• pixm
• pmsui
• psplash
• videofe
• xeoncfg

Note: if you start the docker image first, then start a screen session inside it (to run cdtools) you could do the app builds there, but the docker image is Debian anyway.