MacOSX11.sdk fails to install on MacOSX10.14 & 10.15 with: The requested URL returned error: 403 Forbidden

[jbflanman]

When trying to install MacOSX11.sdk on MacOSX10.14 & 10.15 it fails with message:

sudo port install MacOSX11.sdk
--->  Computing dependencies for MacOSX11.sdk
--->  Fetching archive for MacOSX11.sdk
--->  Attempting to fetch MacOSX11.sdk-11.3.1-20E241_0+universal.darwin_18.arm64-x86_64.tbz2 from http://packages.macports.org/MacOSX11.sdk
--->  Attempting to fetch MacOSX11.sdk-11.3.1-20E241_0+universal.darwin_18.arm64-x86_64.tbz2 from http://ywg.ca.packages.macports.org/mirror/macports/packages/MacOSX11.sdk
--->  Attempting to fetch MacOSX11.sdk-11.3.1-20E241_0+universal.darwin_18.arm64-x86_64.tbz2 from http://mirror.fcix.net/macports/packages/MacOSX11.sdk
--->  Fetching distfiles for MacOSX11.sdk
--->  Attempting to fetch CLTools_macOSLMOS_SDK.pkg from https://swcdn.apple.com/content/downloads/28/19/071-82714-A_HUFJRGID6Y/nnmlg28zs93jdbrsqtk6krr4mmaize40hb
Error: Failed to fetch MacOSX11.sdk: The requested URL returned error: 403 Forbidden
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_MacOSX.sdk/MacOSX11.sdk/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets if you believe there is a bug.
Error: Processing of port MacOSX11.sdk failed

Seems like there is a permissions issue. MacOSX10.14.sdk and MacOSX10.15.sdk installed as expected on both OS's. main.log files for each fail attached.

[jbflanman]

MacOSX11.sdk main.log file from failures on 10.14

[jbflanman]

MacOSX11.sdk main.log file from failures on 10.15

[jbflanman]

Just stumbled accross #69952. Not sure why I didn't find it before I submitted my bug.

Followed link to "fix" at ​https://github.com/macports/macports-ports/pull/23312 and read through the discussion.

It doesn't seem like a correct URL has been found or the CLT dmg's are easily available from Apple.