Facilitate installing pacman in Git for Windows, started from this StackOverflow answer.
Each release adds a new package-versions-X.YY.Z.txt file in the versions folder of the build-extra project. Open that version file and copy the line starts with "mingw-w64-x86_64-git " (a space immediately after the 't'). For example,
mingw-w64-x86_64-git 2.39.1.1.b03dafd9c2-1
Paste that as a new line in the version-tags.txt file. Paste it to another new line for the 32-bit version and replace 'x65_64' with 'i686'. For example,
mingw-w64-i686-git 2.39.1.1.b03dafd9c2-1
Click and open this release page and find that version. Hover on the release date on the left hand column (above the git-for-windows-ci icon) to get the exact date and time of the release. For example,
Jan 17, 2023, 10:05 AM PST
Open this 64-bit SDK commit history page. Find the commit ID with a date and time closest to but before the release time. Hover on the date after the word "committed" or "committed on" to get the exact date and time. For example, a commit on 'Jan 17, 2023, 7:07 PM PST' is the wrong one for the above release date. Copy the commit ID and append it with a space to the new 'x86_64' line in version-tags.txt.
Open this 32-bit SDK commit history page. Find the commit ID with a date and time closest to but before the release time. Copy the commit ID and append it with a space to the new 'i686' line in version-tags.txt.