Hello,  Andrey !

> !!! Fetch for /usr/local/sci/app-office/texmacs/texmacs-1.0.6.8.ebuildfailed,
> continuing...
Are you sure that you have fetched an uncorrupted copy of
TeXmacs-1.0.6.8-src.tar.gz ? My copy has the size 3835265.
Manifest has been generated from this copy, and contains this size (and
texmacs-1.0.6.8 emerges without any problems).

Of course yes, I have downloaded this file  and archive was opened and unpacked without any problems.

--
Best regards,
Sincerely yours,
Yuriy Rusinov