Bug#993832: synfig FTBFS with mlt 7

[Adrian Bunk]

Source: synfig
Version: 1.4.0+dfsg-2
Severity: serious
Tags: ftbfs bookworm sid

https://buildd.debian.org/status/package.php?p=synfig&suite=sid

...
checking for mlt++... configure: error:  ** You need to install mlt++.