asymptote @2.70: source download fails

[captainproton1971 (Captain Proton)]

port upgrade failing because of source download problem:

--->  Attempting to fetch asymptote-2.70.src.tgz from http://iweb.dl.sourceforge.net/asymptote
--->  Verifying checksums for asymptote                                              
Error: Checksum (rmd160) mismatch for asymptote-2.70.src.tgz
Error: Checksum (sha256) mismatch for asymptote-2.70.src.tgz
Error: Checksum (size) mismatch for asymptote-2.70.src.tgz
***
The non-matching file appears to be HTML. See this page for possible reasons
for the checksum mismatch:
<https://trac.macports.org/wiki/MisbehavingServers>
***
The file has been moved to: /opt/local/var/macports/distfiles/asymptote/asymptote-2.70.src.tgz.html
Error: Failed to checksum asymptote: Unable to verify file checksums
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_asymptote/asymptote/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.

[captainproton1971 (Captain Proton)]

Log file

[mojca (Mojca Miklavec)]

This looks like a broken server to me (or one that didn't do any updates recently) that just served you some "file not found" HTML document.

[mf2k (Frank Schima)]

In the future, please fill in the Port field.

[jmroot (Joshua Root)]

See #62325. It's apparently not safe to rely on redirects with sourceforge mirrors.

[ryandesign (Ryan Carsten Schmidt)]

In 79fc72ca89404e063b2949aeffdd7675c3006114/macports-ports (master):

asymptote: Avoid http redirects

Closes: #62583