libxkbcommon slackbuild fails; portues (slackware 14.2+)

I'm trying to get opera running on porteus (slackware 14.2+)
opera needs libxkbcommon and so I am trying to install it via slackbuild.
The build fails with error:
Quote:

Saving to: /tmp/slpkg/build/_SOURCES/meson-0.55.3.tar.gz' <...> +======================================================================= | MD5SUM check for meson-0.55.3.tar.gz [ PASSED ] +======================================================================== tar: /tmp/slpkg/build/meson/meson-0.57.1.tar.gz: Cannot open: No such file or directory tar: Error is not recoverable: exiting now

As u can see the version saved is 55.3 but tar is trying to work with 57.1
(Incidentally, I saw a similar error with another package)
So is this something to do with packaging? How to fix,please?

TIA