We no longer rely on git tags and git describe output, since it's
hard to reliably select the correct tag eg for minor releases.
We might use them again in future for dev builds, but it requires
adding git describe --match support to githash. For now,
* Program name, OS and architecture are always shown.
* The package version is always shown.
* If there is git info at build time, the latest commit hash and commit date are shown.
Example outputs:
A homebrew binary, not built in git repo: hledger-ui 1.24, mac-aarch64
A CI release build, built in git repo: hledger 1.24.1-g455b35293-20211210, mac-x86_64
API changes:
* new type synonyms ProgramName, PackageVersion, VersionString
* versionStringForProgname -> versionString with extra argument
* versionStringFor -> versionStringWith with extra argument
to Hledger.Cli.
Since the git hash changes whenever any file in the repository changes,
this means Hledger.Cli.Version needs to be recompiled all the time.
Since it is at the bottom of the module hierarchy, this means that the
whole hledger package needs to be recompiled. We instead move the
TemplateHaskell splice to one of the top modules, so much less needs to
be recompiled.
Note: Ghc seems to be able to get out of most of the recompiling a lot
of the time (due to caching?), but this makes things more reliable.
hledger and hledger-web were reading their version number (and program
name) from their cabal files at compile time using cabal-file-th,
which allowed the version number be maintained in one place (per
package).
This meant you had to be in same directory as the cabal file when
building, which made life more complicated, eg emacs compilation mode
could not jump to errors. Also, it slowed down building slightly, and
is a factor in hledger Debian packages being unavailable on a number
of platforms (we also use TH for report templates).
Now, the build version is set with a CPP VERSION flag, which seems
simpler overall. For cabal builds, this needs to be configured
manually in a few more places in each cabal file. For makefile builds,
it is set it to the name of the most recent darcs tag (which should be
more useful than the old behaviour). If not set, it defaults to the
blank string, useful eg for haddock. And, all makefile builds now run
from the top directory.
