4 This is a wrapper tool for `cargo`, the Rust build tool and package
7 * Conveniently use local crates, including completely
10 * Perform out-of-tree builds, including in an account with
11 no write access to the source tree.
13 * Provide convenience aliases for target architecture names.
15 * Makes the default be offline (ie, not to access the internet)
17 These functions are of course configurable.
19 The primary source of information for `nailing-cargo` is the file
20 `../Cargo.nail` (which is in TOML syntax). You put `Cargo.nail`
21 alongside the top-level git repositories you are working with, and
22 invoke nailing-cargo from the git directory containing the Rust
23 package you want to build.
28 nailing-cargo is designed to be run out of a git clone:
31 $ git clone https://salsa.debian.org/iwj/nailing-cargo.git
32 $ ln -s `pwd`/nailing-cargo/nailing-cargo ~/bin
35 It is self-contained, depending only on a reasonably functional Perl
38 Most basic example usage
39 ------------------------
48 $ nailing-cargo cargo generate-lockfile
49 $ nailing-cargo cargo build
52 Using local crates, or locally modified crates
53 ==============================================
55 cargo does not work well with local crates,
56 especially completely unpublished ones.
57 (See [issue#6713](https://github.com/rust-lang/cargo/issues/6713),
58 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),
59 [issue#1481](https://github.com/rust-lang/cargo/issues/1481),
60 [my blog](https://diziet.dreamwidth.org/1805.html).)
62 Using a local version of a crate should be possible without putting
63 paths into your `Cargo.toml` and without editing complex
66 How nailing-cargo helps with using local crates
67 -----------------------------------------------
69 nailing-cargo temporarily edits all the `Cargo.toml` files in all the
70 subdirectories you mention, to refer to each other; then it runs
71 cargo; and then it puts everything back.
73 Telling nailing-cargo how to massage Cargo.toml
74 -----------------------------------------------
76 To find the subdirectories, and the packages, it looks for `subdirs`
77 and `packages` in `Cargo.nail`.
79 `subdirs` can be a (usually multi-line) string containing a list of
80 subdirectory names one per line. (`#`-comments are supported.) Or it
81 can be a list of strings (`subdirs = ['myproject','mylibrary']`). In
82 each of these directories `Cargo.toml` will be massaged, and
83 the package there will be used for other massaged `Cargo.toml`s
85 For more complex cases: `packages` is a mapping from package names to
86 strings, or dictionaries (e.g. in `Cargo.nail`, write something like:
87 `[packages.mylibrary]` `subdir='mylibrary-test'` or `[packages]`
88 `mylibrary='mylibrary-test'`). These override the locations for the
89 specified packages (so you can, for example, have multiple trees with
90 the same package in). The `subdir` values are also added to the list
91 of directories where `Cargo.toml` should be massaged.
96 It is often desirable to run builds in a way that does not write to
97 the source tree. cargo's enthusiastic approach to the dependency
98 management task means that it is a good idea to try to insulate your
99 main working environment from the many things cargo has decided to
100 download and execute.
102 However, when you tell cargo to do an out of tree build (using
103 `--manifest-path`) it will insist on `Cargo.lock` being in the source
104 directory, and often will insist on writing to it.
106 How nailing-cargo helps with out-of-tree builds
107 -----------------------------------------------
109 nailing-cargo (configured appropriately) copies files back and forth
110 to between the source and build directories, and runs cargo as your
113 The `Cargo.lock` must still be saved in your source tree somewhere.
114 nailing-cargo arranges this for you. You can either put this file in
115 `.gitignore`; or commit it to git; or you can tell nailing-cargo to
116 save it as something like `Cargo.lock.example`.
118 Configuring out-of-tree builds
119 ------------------------------
121 To enable out-of-tree-builds, put an `[oot]` section in your
122 `Cargo.nail` or one of nailing-cargo's other config files.
123 In that section, specify at least `use`.
125 The primary config keys here are:
127 * `dir`: The build directory. If relative, it is relative to the
128 parent of the invocation directory (and could be a symlink then).
129 Default is `Build` (assuming `use` is specified).
131 * `use`: How to become the build user. Needs to be combined
132 with other setting(s):
134 * `ssh`: Use ssh. `user` must be given as well and is
135 the `<user>@<host>` argument to ssh.
137 * `command_args`: `command` must be specified as a list,
138 specifying a command and arguments which work like `nice`.
140 * `command_sh`: `command` must be specified as a list,
141 specifying a command and arguments which work like `sh -c`.
143 * `null`: Run builds as the same user.
145 * `really`: Use `really` from `chiark-really.deb`.
146 `user` must be given as well.
148 Target architecture convenience aliases
149 =======================================
151 If you are cross-building you may need to tell cargo `--target=`.
152 The architecture names are quite long and inconvenient.
154 A simple shell alias would help a lot, except that cargo rejects
155 `--target=` when it thinks it's not needed.
157 In your nailing-cargo config, you can write something like
158 `arch.RPI='arm-unknown-linux-gnueabihf'`. Then `nailing-cargo -ARPI`
159 will DTRT. In fact, you do not even need to specify that particular
160 arch alias, since it is built-in to nailing-cargo.
162 Default change to offline mode
163 ==============================
165 It seems to me that build tools should be explicit about their use of
166 the network. So by default, nailing-cargo passes `--offline` to
169 If you disagree with my opinion, write `misc.online=true` in your
170 nailing-cargo configuration. `misc.online=false`, and command line
171 options, are also available, for overriding.
176 * `-v`: Increase verbosity. Default is 1.
178 * `-q`: Set verbosity to 0.
180 * `-D`: Increase amount of debugging dump.
182 * `-n`: "No action": stop after writing Cargo.toml.nailing~
183 everywhere, and do not run any build command.
185 * `-A<arch>` | `--arch=<arch>` | `--target=<arch>`
187 Specify target architecture. If `<arch>` starts with a capital
188 ascii letter, is an alias for some other arch: it is looked up
189 in the configuration, and then in the builtin arch alias list.
190 The builtin list is equivalent to: `[arch]`
191 `RPI='arm-unknown-linux-gnueabihf'`.
193 This option translates to a --target= option to the ultimate
194 command, unless that is a cargo subcommand which we know
195 would reject it. `--arch` and `--target` are simply aliases.
197 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
199 Enables, or disables, the dance to allow Cargo.lock (or
200 alternative) to be updated in the source directory.
202 With this dance enabled the Cargo.lock and Cargo.toml are
203 copied to the build directory along with a skeleton just big
204 enough to fool cargo. After cargo has run, the resulting
205 Cargo.lock is copied back to the source tree.
207 This makes no sense with in-tree builds.
209 Default is no update unless the ultimate command is a
210 cargo subcommand which we know needs it.
212 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
214 Controls whether we add cargo command line options relating to
215 finding `Cargo.toml`, to the command to run.
217 Default is to add them if we are doing an out-of-tree build,
218 unless we are doing the dance to update the `Cargo.lock` (see
219 above) since in that case all the relevant files can be found
220 by cargo in the build directory.
222 The arguments added are
224 --manifest-path=<path/to/Cargo.toml>
228 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
230 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
231 makes any difference with `-m`, since otherwise no
232 `--target-dir` would be passed anyway. Additionally this is
233 done automatically when nailing-cargo sees that the cargo
234 subcommand is one which needs it, eg `fetch'.
236 * `-o` | `--online` | `--offline` | `-O`
238 Whether to allow cargo to make network access. nailing-cargo
239 always passes `--offline` to cargo, unless `--online` is in
240 force. The default is offline, unless the cargo subcommand is
241 one which implies online (currently, `fetch').
246 nailing-cargo reads these configuration files:
248 /etc/nailing-cargo/cfg.toml
249 ~/.nailing-cargo.toml
250 ./.nailing-cargo.toml
251 ../Nailing-Cargo.toml
254 Settings in later-mentioned files override ones in earlier-mentioned
257 Note that unlike everything else, `packages` and `subdirs` are read
258 only from `Cargo.nail` (see "Limitations and bugs", below).
260 Alternative `Cargo.lock` filename
261 ---------------------------------
263 To control use of alternative Cargo.lock filename, use the section
264 `[alt_cargolock]`. Settings here:
266 * `file = false`: disables this feature
268 * `file = true`: equivalent to `file = "Cargo.lock.example"`
269 (this is the default).
271 * `file = <some leafname>`
273 * `force = false`: Use the alternative file only if it
274 already exists. (This is the default.)
276 * `force = true`: Always uses the alternative filename.
281 Normally you pass `cargo` as an argument to `nailing-cargo`. But you
282 can also pass `make` or any other command. You may need to pass
283 `--no-cargo-manifest-args` (aka `-M`) to nailing-cargo, to avoid
284 passing options like `--manifest-path` to `make` or whatever.
286 nailing-cargo passes these environment variables to the build command:
288 * `NAILINGCARGO_WORKSPHERE`: invocation `..` (parent)
289 * `NAILINGCARGO_MANIFEST_DIR`: invocation `.` (invocation directory)
290 * `NAILINGCARGO_BUILD_DIR`: build directory (even if same as source)
291 * `NAILINGCARGO_BUILDSPHERE`: only set if out of tree: parent of build dir.
293 All of these are absolute paths.
298 * nailing-cargo temporarily dirties your source trees, including
299 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
300 crashes or is interrupted these changes may be left behind.
301 Unfortunately it is not possible to avoid this temporary dirtying
302 because the cargo team have deliberately made cargo inflexible -
303 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
304 At least, running nailing-cargo again will clean up any mess
305 left by an interrupted run.
307 * Out of tree builds require a unified filesystem view: eg, different
308 users on the same host, NFS, or something. This could be improved.
310 The alternative Cargo.lock filename must currently be a leafname. I
311 think fixing this just involves review to check other values work
314 * The alternative Cargo.lock file must be on same filesystem. This is
315 not so easy to fix; we would want the existing algorithm but a
316 fallback for this case.
318 * Cargo.nail is unconditionally looked for in the parent directory.
319 Ideally this should be configurable, and also perhaps be able to
320 combine multiple Cargo.nail files? Relatedly, although
321 nailing-cargo can read multiple config files, it can only handle
322 one file specifying directories and packages.
324 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
325 rather than a more sophisticated scheme involving locking
326 particular directories. This means that if you run multiple
327 copies of nailing-cargo at once, in different directories, but
328 with `Cargo.nail` files which imply overlapping sets of package
329 directories, things will go Badly Wrong.
331 Contributing and legal
332 ======================
334 nailing-cargo is Free Software.
336 Please help improve it. Contributions (to address the limitations, or
337 to add new facilities to help work with cargo) are welcome by email to
338 `ijackson@chiark.greenend.org.uk` or via the [Salsa
339 project](https://salsa.debian.org/iwj/nailing-cargo).
341 If you plan to do substantial work, please do get in touch with a
342 sketch of your proposed changes.
347 This project accepts contributions based on the git commit
348 Signed-off-by convention, by which the contributors certify their
349 contributions according to the Developer Certificate of Origin version
350 1.1 - see the file DEVELOPER-CERTIFICATE.
352 Copyright (C) 2019-2020 Ian Jackson and others
354 This program is free software: you can redistribute it and/or modify
355 it under the terms of the GNU Affero General Public License as
356 published by the Free Software Foundation, either version 3 of the
357 License, or (at your option) any later version.
359 This program is distributed in the hope that it will be useful,
360 but WITHOUT ANY WARRANTY; without even the implied warranty of
361 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
362 GNU Affero General Public License for more details.
364 You should have received a copy of the GNU Affero General Public License
365 along with this program. If not, see <http://www.gnu.org/licenses/>.
367 Individual files generally contain the following tag in the copyright
368 notice, instead of the full licence grant text:
370 SPDX-License-Identifier: AGPL-3.0-or-later
372 As is conventional, this should be read as a licence grant.