Failed to install mlton

[anta40 (Andre Tampubolon)]

$ sudo port install mlton
Password:
--->  Computing dependencies for mlton
The following dependencies will be installed:  mlton-bootstrap
Continue? [Y/n]: Y
--->  Fetching archive for mlton-bootstrap
Warning: Your DNS servers incorrectly claim to know the address of nonexistent hosts. This may cause checksum mismatches for some ports. See this page for more information: <https://trac.macports.org/wiki/MisbehavingServers>
--->  Attempting to fetch mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 from http://jog.id.packages.macports.org/macports/packages/mlton-bootstrap
--->  Attempting to fetch mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 from https://packages.macports.org/mlton-bootstrap
--->  Attempting to fetch mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 from https://mirror.sjtu.edu.cn/macports/packages/mlton-bootstrap
--->  Verifying checksums for mlton-bootstrap
Error: Failed to checksum mlton-bootstrap: mlton-20210117-1.amd64-darwin-19.6.gmp-homebrew.tgz does not exist in /opt/local/var/macports/distfiles/mlton-bootstrap
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_mlton-bootstrap/mlton-bootstrap/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets if you believe there is a bug.
Error: Processing of port mlton failed

Examining the log, perhaps this is the cause:

$ cat /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_mlton-bootstrap/mlton-bootstrap/main.log
...
...
:info:archivefetch --->  mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 doesn't seem to exist in /opt/local/var/macports/incoming/verified
:msg:archivefetch --->  Attempting to fetch mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 from http://jog.id.packages.macports.org/macports/packages/mlton-bootstrap
:debug:archivefetch Fetching archive failed: The requested URL returned error: 404
:msg:archivefetch --->  Attempting to fetch mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 from https://packages.macports.org/mlton-bootstrap
:debug:archivefetch Fetching archive failed: The requested URL returned error: 404
:msg:archivefetch --->  Attempting to fetch mlton-bootstrap-20210117_0.darwin_21.x86_64.tbz2 from https://mirror.sjtu.edu.cn/macports/packages/mlton-bootstrap
:debug:archivefetch Fetching archive failed: The requested URL returned error: 403
:debug:archivefetch Privilege de-escalation not attempted as not running as root.
:debug:archivefetch Skipping completed org.macports.fetch (mlton-bootstrap)
...