Libraries missing for measuing temperature on Raspberry

[fede2cr]

I was trying to check the Raspberry Pi's temp during the test, but it seems that a couple of libraries are missing from the distribution.

lepidopter@lepidopter:$ /opt/vc/bin/vcgencmd measure_temp
/opt/vc/bin/vcgencmd: error while loading shared libraries: libvchiq_arm.so: cannot open shared object file: No such file or directory
lepidopter@lepidopter:$ ldd /opt/vc/bin/vcgencmd
linux-vdso.so.1 (0x7ecad000)
libvchiq_arm.so => not found
libvcos.so => not found
libpthread.so.0 => /lib/arm-linux-gnueabi/libpthread.so.0 (0x76f70000)
libdl.so.2 => /lib/arm-linux-gnueabi/libdl.so.2 (0x76f5d000)
librt.so.1 => /lib/arm-linux-gnueabi/librt.so.1 (0x76f46000)
libc.so.6 => /lib/arm-linux-gnueabi/libc.so.6 (0x76dfc000)
/lib/ld-linux.so.3 (0x54ae7000)

[anadahz]

The libraries are there but the PATH for LDLIBRARYPATH is missing.
You can temporarily set the PATH with export:
export LD_LIBRARY_PATH=$LD_LIBRARYPATH:/opt/vc/lib

To make the changes permanent add the export command to a file in /etc/profile.d/.

In order to run /opt/vc/bin/vcgencmd as lepidopter, you should add the user lepidopter to the video group.

---

Another way to get the current temperature without using any program is to read the content of the file /sys/class/thermal/thermal_zone0/temp you can pretty print the temperature:

echo $((`cat /sys/class/thermal/thermal_zone0/temp|cut -c1-2`)).$((`cat /sys/class/thermal/thermal_zone0/temp|cut -c3-5`))

Thank you for reporting this.

[koushikcs562]

Hello @fede2cr and @anadahz,
Thank you for clarifying that this is an issue with the missing $LD_LIBRARY_PATH. The temporary fix provided by @anadahz is helpful for diagnosis, but a permanent fix is needed in the image distribution.
I'd be interested in submitting a PR to fix this permanently in the build script.
My Approach (Permanent Fix for Distribution)
Set LD_LIBRARY_PATH: I will modify the Lepidopter build script (likely in a vmdebootstrap step or equivalent) to permanently set the $LD_LIBRARY_PATH. This will be achieved by creating a configuration file in /etc/ld.so.conf.d/ that points to /opt/vc/lib. This is the preferred, system-wide method over using /etc/profile.d/.
Add User to Group: I will also ensure the lepidopter user is added to the video group during the build process to grant the necessary permissions to execute /opt/vc/bin/vcgencmd without issues.