Discussion
About the plan for today... if I'd want to do it right, it would be a "little bit" more involved. Ideally, I'd have a derivation for the tarball too.
Maybe I should. I mean, I have to implement derivations in a less hacky way than in an earlier (unpublished) PoC, and that will involve builders.
input pkgin builder=pkgin
Ideally, that'll yield an output that transforms the pkg_summary.bz2 and SHA512.bz2 files into something fuck can work with directly. Thus, I'd parse them once, and then use whatever format I end up with.
I suppose the easiest thing would be to build a directory of derivations:
❯ tree .
.
└── packages
├── 0verkill
│ ├── 0verkill-0.16nb1.tgz.drv
│ └── current.drv -> 0verkill-0.16nb1.tgz.drv
└── fasttracker2
├── current.drv -> fasttracker2-2.19.tgz.drv
└── fasttracker2-2.19.tgz.drv
Don't need hashes in the filenames here, because . will be /sexshop/toys/$hash-pkgin-summary anyway, and the derivations will have the targz sha512 hashes too.
Then, when interpreting a package from=pkgin jq, that'll look for packages/jq/current.drv, build that, done.
Well, okay, there's a problem: input pkgin builder=pkgin would need to make a derivation, but what's the hash of that?
Ideally, I'd point an input to an exact point in time, but that's not an option in this case, so the input is non-deterministic.
...what if I didn't store the derivation in the store in this case? I'd build a .drv-like thing, in memory. I'd store the downloaded pkg_summary.bz2 and SHA512.bz2 in the store, though, because I can compute a hash for those.
I also need to figure out how to compute the hash of an output that has multiple files, directories, possibly symlinks and the like.
I guess walking the directory, and computing the hash of ${path}\0${type}\0${content}\0 (where ${content}\0 is optional, only present when the path is a regular file) would do, on top of hashing the dependency paths.
Or, the hash could be builder-specific, and the builder would be responsible for nooping out when the output is already in the store.
In any case, it increasingly feels like I don't want to model these steps as discrete CLI commands, and I should start implementing the configuration evaluator, because input pkgin builder=pkgin is much more convenient than:
❯ fuck input pkgin | fuck build -
Both to use, and to implement.
Sooo... new plan!
I will start implementing fuck properly, starting from a higher level, with good error messages, progress bars, parallel execution where possible, all that stuff.
Since initially it will all be in Rust, with some shelling out here and there, this allows me to build the kind of tool I'd like to use, as friendly as possible.
I'll figure out how to abstract some of it away to let parts of it be script-controlled.
Also... what should I use as the .drv format? JSON would be the obvious choice, but that requires serde and serde_json, and I'd love if I didn't have to do that.
What if it was KDL too?
There's a certain charm in commands like fuck help.
❯ cargo run -q build
Error: × No such file or directory (os error 2)
help: Ensure that `fuck.kdl` exists, and is readable.
Because I'm not a caveman, my errors will include helpful hints, such as which file a particular error refers to. Because "No such file or directory" in itself is pointless and useless noise1.
Looking at most software that just prints strerror(errno), which is too many of them. ↩︎
❯ cargo run -q -- build
Error: × Permission denied (os error 13): fuck.kdl
help: Ensure that `fuck.kdl` exists, and is readable.
So far so good.
❯ cargo run -q -- build
Error: × Failed to parse KDL document
Error:
× Non-digit character found after the '.' of a float
╭────
1 │ foo 1.
· ─┬─
· ╰── not float
╰────
Now this needs improvement: gotta change the top-level error to include the filename.
❯ cargo run -q -- build
Error: × Failed to read configuration from `fuck.kdl`
╰─▶ Failed to parse KDL document
Error:
× Non-digit character found after the '.' of a float
╭────
1 │ foo 1.
· ─┬─
· ╰── not float
╰────
There we go. .wrap_err_with() to the rescue!
I think it's time to split out fuck from the fuckery repo soon.
...but also, low on spoons today, so I'll have a little Diablo IV break.
Install bonfire.cafe
Get the full app experience
Which in turn means that my inputs are a derivation too, and the importer I wrote is a builder. Hmm.