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 * Make 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56 especially completely unpublished ones.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58 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),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 For straightforward use, write `subdirs` as a multi-line string
80 containing a list of subdirectory names one per line. In each of
81 these directories `Cargo.toml` will be massaged, and the package there
82 will be used for other massaged `Cargo.toml`s.
84 See "Configuration", below, for the full reference.
89 It is often desirable to run builds in a way that does not write to
90 the source tree. cargo's enthusiastic approach to the dependency
91 management task means that it is a good idea to try to insulate your
92 main working environment from the many things cargo has decided to
95 However, when you tell cargo to do an out of tree build (using
96 `--manifest-path`) it will insist on `Cargo.lock` being in the source
97 directory, and often will insist on writing to it.
99 How nailing-cargo helps with out-of-tree builds
100 -----------------------------------------------
102 nailing-cargo (configured appropriately) copies files back and forth
103 to between the source and build directories, and runs cargo as your
106 The `Cargo.lock` must still be saved in your source tree somewhere.
107 nailing-cargo arranges this for you. You can either put this file in
108 `.gitignore`; or commit it to git; or you can tell nailing-cargo to
109 save it as something like `Cargo.lock.example`.
111 Configuring out-of-tree builds
112 ------------------------------
114 To enable out-of-tree-builds, put an `[oot]` section in your
115 `Cargo.nail` or one of nailing-cargo's other config files.
116 In that section, specify at least `use`.
118 Also, specify `dir`, or create a symlink `Build` next to `Cargo.nail`,
119 pointing to to your build area.
127 will have nailing-cargo run `ssh rustcargo@localhost` to
130 Target architecture convenience aliases
131 =======================================
133 If you are cross-building you may need to tell cargo `--target=`.
134 The architecture names are quite long and inconvenient.
136 A simple shell alias would help a lot, except that cargo rejects
137 `--target=` when it thinks it's not needed.
139 In your nailing-cargo config, you can write something like
140 `arch.RPI='arm-unknown-linux-gnueabihf'`. Then `nailing-cargo -ARPI`
141 will DTRT. In fact, you do not even need to specify that particular
142 arch alias, since it is built-in to nailing-cargo.
144 Default change to offline mode
145 ==============================
147 It seems to me that build tools should be explicit about their use of
148 the network. So by default, nailing-cargo passes `--offline` to
151 If you disagree with my opinion, write `misc.online=true` in your
152 nailing-cargo configuration. `misc.online=false`, and command line
153 options, are also available, for overriding.
158 * `-v`: Increase verbosity. Default is 1.
160 * `-q`: Set verbosity to 0.
162 * `-D`: Increase amount of debugging dump.
164 * `-n`: "No action": stop after writing `Cargo.toml.nailing~`
165 everywhere, and do not run any build command.
167 * `-A<arch>` | `--arch=<arch>` | `--target=<arch>`
169 Specify target architecture.
171 This option translates to a `--target=<arch>` option to the
172 ultimate command, unless that is a cargo subcommand which we
173 know would reject it. `--arch` and `--target` are simply
176 If `<arch>` starts with a capital ascii letter, it is an alias
177 for some other arch: it is looked up in the configuration, and
178 then in the builtin arch alias list. The builtin list is
179 equivalent to: `[arch]` `RPI='arm-unknown-linux-gnueabihf'`.
181 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
183 Enables, or disables, the dance to allow `Cargo.lock` (or
184 alternative) to be updated in the source directory.
186 With this dance enabled the `Cargo.lock` and `Cargo.toml` are
187 copied to the build directory along with a skeleton just big
188 enough to fool cargo. After cargo has run, the resulting
189 `Cargo.lock` is copied back to the source tree.
191 This makes no sense with in-tree builds.
193 Default is no update unless the ultimate command is a
194 cargo subcommand which we know needs it.
196 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
198 Controls whether we add cargo command line options, relating to
199 finding `Cargo.toml`, to the command to run.
201 Default is to add them if we are doing an out-of-tree build,
202 unless we are doing the dance to update the `Cargo.lock` (see
203 above) since in that case all the relevant files can be found
204 by cargo in the build directory.
206 The arguments added are
208 --manifest-path=<path/to/Cargo.toml>
212 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
214 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
215 makes any difference with `-m`, since otherwise no
216 `--target-dir` would be passed anyway. Additionally this is
217 done automatically when nailing-cargo sees that the cargo
218 subcommand is one which needs it, eg `fetch`.
220 * `-o` | `--online` | `-O` | `--offline`
222 Whether to allow cargo to make network access. nailing-cargo
223 always passes `--offline` to cargo, unless `--online` is in
224 force. The default is offline, unless the cargo subcommand is
225 one which implies online (currently, `fetch`).
230 nailing-cargo reads these configuration files:
232 /etc/nailing-cargo/cfg.toml
233 ~/.nailing-cargo.toml
234 ./.nailing-cargo.toml
235 ../Nailing-Cargo.toml
238 Settings in later-mentioned files override ones in earlier-mentioned
241 Source directories and packages (toplevel)
242 ------------------------------------------
244 Note that unlike everything else, these keys `packages` and `subdirs`
245 are read only from `Cargo.nail` (see "Limitations and bugs", below).
247 These keys specify a combination of (i) a mapping from package name to
248 source subdirectory (ii) a set of subdirectories whose `Cargo.toml`
251 * `packages`: a map keyed by package name, giving the subdirectory
254 This causes each mentioned subdirectory's `Cargo.toml` to be
255 massaged, and records that subdirectory as the source for that
256 package. (nailing-cargo will check that subdirectory actually
257 contains the indicated package.)
259 Each value can be just the subdirectory name (eg `[packages]`
260 `mylibrary='mylibrary-test'`) or itself a map with the key `subdir`
261 (eg `[packages.mylibrary]` `subdir='mylibrary-test'`).
263 * `subdirs`: a list of subdirectory names to process.
265 Each subdirectory's `Cargo.toml` will be massaged; also, the
266 subdirectory will be examined to see what package it contains and
267 it will be used as the source for that package, unless that
268 package appears in an entry in `packages`, or an earlier entry in
271 This can be a list of strings (eg `subdirs =
272 ['myproject','mylibrary']`). Or it can be single multi-line
273 string containing one subdirectory name per line; in that
274 case, `#`-comments are supported and tabs and spaces are ignored
275 (See "Most basic example usage" above.)
277 In each case the subdirectory should usually be a relative pathname;
278 it is relative to the directory containing `Cargo.nail`.
280 `[alt_cargolock]`: Alternative `Cargo.lock` filename
281 ----------------------------------------------------
283 To control use of alternative `Cargo.lock` filename, use the section
284 `[alt_cargolock]`. Settings here:
286 * `file = <some leafname>`.
288 * `file = true`: Equivalent to `file = "Cargo.lock.example"`.
289 (This is the default.)
291 * `file = false`: Disables this feature.
293 * `force = false`: Uses the alternative filename only if it
294 already exists. (This is the default.)
296 * `force = true`: Always uses the alternative filename.
298 `[oot]`: Out-of-tree build support
299 ----------------------------------
301 * `dir`: The build directory. If relative, it is relative to the
302 parent of the invocation directory (and could be a symlink then).
303 Default is `Build` (assuming `use` is specified).
305 The build directory will contain one subdir for each package: each
306 subdir in the build dir corresponds to one source dir where
307 nailing-cargo was invoked. nailing-cargo will arrange to create
308 these subdirectories, so the build directory can start out empty.
310 * `use`: How to become the build user. Needs to be combined
311 with other setting(s):
313 * `ssh`: Use ssh. `user` must be given as well and can be
314 a username on localhost, or the `<user>@<host>`
317 * `command_args`: `command` must be specified as a list,
318 specifying a command and arguments which work like `nice`.
320 * `command_sh`: `command` must be specified as a list,
321 specifying a command and arguments which work like `sh -c`.
323 * `null`: Run builds as the same user.
325 * `really`: Use `really` from `chiark-really.deb`.
326 `user` must be given as well.
328 * `command`: The command to run for `command_sh` or `command_args`.
330 * `user`: The local username for `really` and `ssh`, or
331 `<user>@<host>` for `ssh`.
336 Normally you pass cargo as an argument to nailing-cargo. But you
337 can also pass make or any other command. You may need to pass
338 `--no-cargo-manifest-args` (aka `-M`) to nailing-cargo, to avoid
339 passing options like `--manifest-path` to make or whatever.
341 nailing-cargo passes these environment variables to the build command:
343 * `NAILINGCARGO_WORKSPHERE`: invocation `..` (parent)
344 * `NAILINGCARGO_MANIFEST_DIR`: invocation `.` (invocation directory)
345 * `NAILINGCARGO_BUILD_DIR`: build directory (even if same as source)
346 * `NAILINGCARGO_BUILDSPHERE`: only set if out of tree: parent of build dir.
348 All of these are absolute paths.
353 * nailing-cargo temporarily dirties your source trees, including
354 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
355 crashes or is interrupted these changes may be left behind.
356 Unfortunately it is not possible to avoid this temporary dirtying
357 because the cargo team have deliberately made cargo inflexible -
358 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
359 At least, running nailing-cargo again will clean up any mess
360 left by an interrupted run.
362 * Out of tree builds require a unified filesystem view: eg, different
363 users on the same host, NFS, or something.
365 Specifically, the invocation and build execution environments must
366 both have visibility of the source and build directories, at the
367 same absolute pathnames. The invocation environment must be able
368 to write to the build environment (but vice versa is not
371 This could be improved.
373 * The alternative `Cargo.lock` filename must currently be a leafname. I
374 think fixing this just involves review to check other values work
377 * The alternative `Cargo.lock` file must be on the same filesystem
378 as the source tree. This is not so easy to fix; we would want the
379 existing algorithm but a fallback for the different-filsystem case.
381 * `Cargo.nail` is unconditionally looked for in the parent directory.
382 Ideally this should be configurable, and also perhaps be able to
383 combine multiple `Cargo.nail` files? Relatedly, although
384 nailing-cargo can read multiple config files, it can only handle
385 one file specifying directories and packages.
387 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
388 rather than a more sophisticated scheme involving locking
389 particular directories. This means that if you run multiple
390 copies of nailing-cargo at once, in different directories, but
391 with `Cargo.nail` files which imply overlapping sets of package
392 directories, things will go Badly Wrong.
394 Contributing and legal
395 ======================
397 nailing-cargo is Free Software.
399 Please help improve it. Contributions (to address the limitations, or
400 to add new facilities to help work with cargo) are welcome by email to
401 `ijackson@chiark.greenend.org.uk` or via the [Salsa
402 project](https://salsa.debian.org/iwj/nailing-cargo).
404 If you plan to do substantial work, please do get in touch with a
405 sketch of your proposed changes.
410 This project accepts contributions based on the git commit
411 Signed-off-by convention, by which the contributors certify their
412 contributions according to the Developer Certificate of Origin version
413 1.1 - see the file DEVELOPER-CERTIFICATE.
415 Copyright (C) 2019-2020 Ian Jackson and others
417 This program is free software: you can redistribute it and/or modify
418 it under the terms of the GNU Affero General Public License as
419 published by the Free Software Foundation, either version 3 of the
420 License, or (at your option) any later version.
422 This program is distributed in the hope that it will be useful,
423 but WITHOUT ANY WARRANTY; without even the implied warranty of
424 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
425 GNU Affero General Public License for more details.
427 You should have received a copy of the GNU Affero General Public License
428 along with this program. If not, see <http://www.gnu.org/licenses/>.
430 Individual files generally contain the following tag in the copyright
431 notice, instead of the full licence grant text:
433 SPDX-License-Identifier: AGPL-3.0-or-later
435 As is conventional, this should be read as a licence grant.