lxterminal-0.2.0's gtk3 build uses vte library 2.90, which was shipped by vte tarballs up to 0.36.
Vte tarball 0.38 changed to an incompatible API, library version 2.91. The previous one is no longer maintained.
The new one is already shipped by every modern distribution. It adds many enhancements and bugfixes; probably the most important is that the scrollbak is no longer stored on disk as plaintext (a security/privacy issue if someone steals the hard drive), it is compressed and encrypted before being written out.
See https://github.com/mate-desktop/mate-terminal/issues/66 for some hints on how to port to the new API.