port install subport=xyz doesnt work as expected

[wadjei]

I'm working on a system which has the last version of MacOS 10.9 Mavericks installed.

I am trying to follow the instructions here ​https://trac.macports.org/wiki/howto/InstallingOlderPort#subport to install an older version of mysql8-server (@8.0.19_0) since the current version will not compile on my system.

This is a subport of databases/mysql8 - I have cloned and checked out an older version of the repository and was able to install mysql8 successfully

$ port installed mysql8
The following ports are currently installed:
  mysql8 @8.0.19_0 (active)

But any attempt to install the same version of mysql8-server results in the current version (8.0.21) being fetched as a dependency which then fails to install.

In the databases/mysql8 directory I'm executing, and seeing

/Users/will/macports-ports/databases/mysql8
helium:mysql8 will$ port info
mysql8 @8.0.19 (databases)
Sub-ports:            mysql8-server
Variants:             debug, universal

Description:          MySQL is an open-source, multi-threaded SQL database.
Homepage:             https://www.mysql.com/

Build Dependencies:   cmake, clang-7.0
Library Dependencies: openssl, cyrus-sasl2, icu, zlib, zstd, legacy-support
Runtime Dependencies: mysql_select
Platforms:            darwin
License:              GPL-2
Maintainers:          Email: herby.gillot@gmail.com, GitHub: herbygillot
                      Policy: openmaintainer
helium:mysql8 will$ sudo port install subport=mysql8-server
--->  Computing dependencies for mysql8
--->  Fetching archive for mysql8
--->  Attempting to fetch mysql8-8.0.21_0.darwin_13.x86_64.tbz2 from http://lil.fr.packages.macports.org/mysql8
--->  Attempting to fetch mysql8-8.0.21_0.darwin_13.x86_64.tbz2 from https://packages.macports.org/mysql8
--->  Attempting to fetch mysql8-8.0.21_0.darwin_13.x86_64.tbz2 from http://mse.uk.packages.macports.org/sites/packages.macports.org/mysql8
--->  Fetching distfiles for mysql8
--->  Verifying checksums for mysql8
--->  Extracting mysql8

which then goes on to fail