`make-tag.py` should construct tag from build system variables

[hebasto]

Currently, the make-tag.py script accepts a desired tag as its argument, which is then compared to the version-specific variables set in the build system:

set(CLIENT_VERSION_MAJOR 29)
set(CLIENT_VERSION_MINOR 99)
set(CLIENT_VERSION_BUILD 0)
set(CLIENT_VERSION_RC 0)
set(CLIENT_VERSION_IS_RELEASE "false")

Wouldn't it be more prudent to construct the tag from the build system variables rather then pass it as an argument and then verify it?

This approach would make the build system variables the single source of truth for the software version details.

Related to bitcoin/bitcoin#31898.

[laanwj]

The reason that it takes a tag on the command line is basically a sanity check.

Sure, it could automatically generate it from information it parses from the build system, but the intent of the user matters; my motivation to write the script back in the day was to ensure that the build system information is correct before tagging. Without passing the to-be-expected tag in, it would create the wrong tag instead if it's not.

[hebasto]

The reason that it takes a tag on the command line is basically a sanity check.

Sure, it could automatically generate it from information it parses from the build system, but the intent of the user matters; my motivation to write the script back in the day was to ensure that the build system information is correct before tagging. Without passing the to-be-expected tag in, it would create the wrong tag instead if it's not.

I agree.

My concern stems from this comment, which assumes that a tag might be a source of version details. And I believe that assumption is incorrect.

[fanquake]

which assumes that a tag might be a source of version details. And I believe that assumption is incorrect.

Can you explain? It is the exact version details that will be used to create the release source tarball.

[fanquake]

This is the chain from git tag to tarball: git tag -> git_head_version -> VERSION -> DISTNAME -> GIT_ARCHIVE="${DIST_ARCHIVE_BASE}/${DISTNAME}.tar.gz". So, I don't understand how the tag is not a source of version details? It's literally what names the tarball.

[hebasto]

This is the chain from git tag to tarball: git tag -> git_head_version -> VERSION -> DISTNAME -> GIT_ARCHIVE="${DIST_ARCHIVE_BASE}/${DISTNAME}.tar.gz". So, I don't understand how the tag is not a source of version details? It's literally what names the tarball.

Sure. However, it should never be a random tag but rather one that either passes the make-tag.py script's checks or constructed directly from the build system variables.