chezmoi_modify_manager 3.7.1

# Packaging for Linux distros etc

Do you want to package chezmoi_modify_manager in your favourite package manager?
Awesome! Here are some helpful notes for you.

* Please tell me about your package (file a github issue): I will link to any
  suitable package from the README (with a written caveat that I don't maintain
  them and thus cannot guarantee that they are up-to-date or safe to use). I
  maintain the AUR package myself as of writing this (thus there is no
  disclaimer there).
* If you need some inspiration for how to build and install properly, you might
  want to take a look at my AUR
  [PKGBUILD](https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=chezmoi_modify_manager).
  Arch Linux uses a relatively simply format (bash scripts), so it should be
  easy to decode and adapt.

## How to build

* When building, please export the environment variable
  `CHEZMOI_MODIFY_MANAGER_BUILDER`. This will be reported in
  `chezmoi_modify_manager --doctor`, and can be very helpful in bug reports.
  If you don't set this, `--doctor` will report it as a warning (assuming that it
  is an unknown local build on someone's computer).
  * Please set it to a short and truthful value (such as "debian", "homebrew",
    "aur" etc) that identifies the package ecosystem. If your package build the
    latest and greatest git version, please add a suffix indicating so (e.g. "aur-git")
  * Especially don't claim to be "github-ci" or "github-release" as those are used
    for the official binary releases. That would be Not Cool!
* Build a release build (`--release`). Rust is really quite slow in debug
  builds, but very speedy in release builds. The difference between debug and
  release builds is much larger than for C/C++.
* Build with `--locked`: This ensures that the versions of dependencies are
  exactly the same as upstream. Otherwise, you might get newer supposedly
  compatible versions. Those may or may not work.
* Build with the stable Rust toolchain: Nightly or beta is not needed and is
  just asking for potential issues.
* You likely want to exclude the built-in self updater (that downloads from
  Github releases), as your package manager should be used instead. This is easy:
  pass `--no-default-features --features=keyring` to cargo build. This will also
  avoid vendoring C dependencies (in particular `libdbus`) and instead link them
  dynamically. If you don't want that, add the `vendored` feature as well
  (i.e. `--features=keyring,vendored`).

And so we arrive at the final (reliable regardless of what environment the
user might have) build command:

```bash
export CHEZMOI_MODIFY_MANAGER_BUILDER="<your package ecosystem name>"
export RUSTUP_TOOLCHAIN=stable
export CARGO_TARGET_DIR=target
cargo build --locked --release --no-default-features --features=keyring
```

If you need to download dependencies first (as is best practise for some build
systems) this gets split into two phases:

```bash
# Download deps
export RUSTUP_TOOLCHAIN=stable
cargo fetch --locked --target "$(rustc -vV | sed -n 's/host: //p')"

# Build
export CHEZMOI_MODIFY_MANAGER_BUILDER=aur
export RUSTUP_TOOLCHAIN=stable
export CARGO_TARGET_DIR=target
cargo build --frozen --release --no-default-features --features=keyring
```

Note the change from `--locked` to `--frozen` in the second command here.

## What to install

You should of course install the binary itself `chezmoi_modify_manager`. However,
you might also want to install shell completion files relevant to your platform.
These can be generated by executing the built binary with
`--bpaf-complete-style-<name of shell>`. Here is the code from the AUR PKGBUILD
to do the entire install:

```bash
local _cmd_name="target/release/${pkgname}"
install -Dm0755 -t "$pkgdir/usr/bin/" "$_cmd_name"
mkdir -p "$pkgdir/usr/share/bash-completion/completions/"
mkdir -p "$pkgdir/usr/share/zsh/site-functions/"
mkdir -p "$pkgdir/usr/share/fish/vendor_completions.d/"
"$_cmd_name" --bpaf-complete-style-zsh > "$pkgdir/usr/share/zsh/site-functions/_$pkgname"
"$_cmd_name" --bpaf-complete-style-bash > "$pkgdir/usr/share/bash-completion/completions/$pkgname"
"$_cmd_name" --bpaf-complete-style-fish > "$pkgdir/usr/share/fish/vendor_completions.d/${pkgname}.fish"
# No support to install distro completions in elvish.
# See https://github.com/elves/elvish/issues/1739
#"$_cmd_name" --bpaf-complete-style-elvish
```

For more info on supported shells, see the
[bpaf documentation](https://docs.rs/bpaf/0.9.9/bpaf/_documentation/_2_howto/_1_completion/index.html),
which is the library used by chezmoi_modify_manager to handle command line parsing.