Since the build is reproducible, it should not matter when it was built. If you want to trace a build back to its source, there are much better ways than a timestamp.
I work on a product whose user interface in one place says something like “Copyright 2004-2025”. The second year there is generated from __DATE__, that way nobody has to do anything to keep it up to date.
Pipe something like this into your build system:
date --date "$(git log HEAD --author-date-order --pretty=format:"%ad" --date=iso | head -n1)" +"%Y"Sticking it into --version output is helpful to know if, for example, the Python binary you're looking at is actually the one you just built rather than something shadowing that
I’m not, but I really think I should be. As in, there should be a thing that saves the state of the tree every time I type `make`, without any thought on my part.
This is (assuming Git—or Mercurial, or another feature-equivalent VCS) not hard in theory: just take your tree’s current state and put it somewhere, like in a merge commit to refs/compiles/master if you’re on refs/heads/master, or in the reflog for a special “stash”-like “compiles” ref, or whatever you like.
The reason I’m not doing it already is that, as far as I can tell, Git makes it stupendously hard to take a dirty working tree and index, do some Git to them (as opposed to a second worktree using the same gitdir), then put things back exactly as they were. I mean, that’s what `git stash` is supposed to do, right?.. Except if you don’t have anything staged then (sometimes?..) after `git stash pop` everything goes staged; and if you’ve added new files with `git add -N` then `git stash` will either refuse to work, or succeed but in such a way that a later `git stash pop` will not mark these files staged (or that might be the behaviour for plain `git add` on new files?). Gods help you if you have dirty submodules, or a merge conflict you’ve fixed but forgot to actually commit.
My point is, this sounds like a problem somebody’s bound to have solved by now. Does anyone have any pointers? As things are now, I take a look at it every so often, then remember or rediscover the abovementioned awfulness and give up. (Similarly for making precommit hooks run against the correct tree state when not all changes are being committed.)
Eg
git commit -am “Starting work on this important feature”
# make some changes
git add . && git commit —-squash “I made a change” HEAD
You can also use `git reset —-soft $BRANCH_OR_COMITTISH` to go back to an earlier commit but leave all changes (except maybe new files? Sigh) staged.
You also might check out `git reflog` to find commits you might’ve orphaned.
What I actually did at $LAST_JOB for dev tooling was to build in <commit sha> + <git diff | sha256> which is probably not amazingly reproducible, but at least you can ask "is the code I have right now what's running" which is all I needed.
Finally, there is probably enough flexibility in most build systems to pick between "reuse a cache artifact even if it has the wrong stamping metadata", "don't add any real information", and "spend an extra 45 cpu minutes on each build because I want $time baked into a module included by every other source file". I have successfully done all 3 with Bazel, for example.
> The sections below are currently a historical reference covering FreeBSD's migration from CVS to Subversion.
My apologies! At the end of the day, the point still stands in that SVN isn't a DVCS and so you wouldn't want to be committing unfinished code though, correct?
(I suspect I got FreeBSD mixed up with OpenBSD in my head here, embarrassing.)