cross compile to arm, 32bit, is missing libXtst.so

[att2]

Hello,
I can cross compile my project fine on a virtual Linux Mint 19 machine to aarch64/linux.
I cannot cross compile to arm, 32bit, because one library is missing: /home/arm1/fpc2/cross/lib/arm-linux is missing the file "libXtst.so".
Where to get this file, how to make it?
The lazarus is version 1.8.4 , the compiler is fpc 3.2.0

Any advice greatly appreciated. Just doing "sudo apt-get install libxtst-dev" on the virtual machine did NOT help.

[af0815]

you habe to get the libs from the targetmachine eg. RasPi.