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 generate-lockfile
52 Documentation table of contents
53 -------------------------------
56 Using local crates, or locally modified crates
57 ==============================================
59 cargo does not work well with local crates,
60 especially completely unpublished ones.
61 (See [issue#6713](https://github.com/rust-lang/cargo/issues/6713),
62 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),
63 [issue#1481](https://github.com/rust-lang/cargo/issues/1481),
64 [my blog](https://diziet.dreamwidth.org/1805.html).)
66 Using a local version of a crate should be possible without putting
67 paths into your `Cargo.toml` and without editing complex
70 How nailing-cargo helps with using local crates
71 -----------------------------------------------
73 nailing-cargo temporarily edits all the `Cargo.toml` files in all the
74 subdirectories you mention, to refer to each other; then it runs
75 cargo; and then it puts everything back.
77 Telling nailing-cargo how to massage `Cargo.toml`
78 -------------------------------------------------
80 To find the subdirectories, and the packages, it looks for `subdirs`
81 and `packages` in `Cargo.nail`.
83 For straightforward use, write `subdirs` as a multi-line string
84 containing a list of subdirectory names one per line. In each of
85 these directories `Cargo.toml` will be massaged, and the package there
86 will be used for other massaged `Cargo.toml`s.
88 See "Configuration reference", below, for full details.
93 It is often desirable to run builds in a way that does not write to
94 the source tree. cargo's enthusiastic approach to the dependency
95 management task means that it is a good idea to try to insulate your
96 main working environment from the many things cargo has decided to
99 However, when you tell cargo to do an out of tree build (using
100 `--manifest-path`) it will insist on `Cargo.lock` being in the source
101 directory, and often will insist on writing to it.
103 How nailing-cargo helps with out-of-tree builds
104 -----------------------------------------------
106 nailing-cargo (configured appropriately) copies files back and forth
107 to between the source and build directories, and runs cargo as your
110 The `Cargo.lock` must still be saved in your source tree somewhere.
111 nailing-cargo arranges this for you. You can either put this file in
112 `.gitignore`; or commit it to git; or you can tell nailing-cargo to
113 save it as something like `Cargo.lock.example`.
115 Configuring out-of-tree builds
116 ------------------------------
118 To enable out-of-tree-builds, put an `[oot]` section in your
119 `Cargo.nail` or one of nailing-cargo's other config files.
120 In that section, specify at least `use`.
122 Also, specify `dir`, or create a symlink `Build` next to `Cargo.nail`,
123 pointing to to your build area.
131 will have nailing-cargo run `ssh rustcargo@localhost` to
134 Target architecture convenience aliases
135 =======================================
137 If you are cross-building you may need to tell cargo `--target=`.
138 The architecture names are quite long and inconvenient.
140 A simple shell alias would help a lot, except that cargo rejects
141 `--target=` when it thinks it's not needed.
143 In your nailing-cargo config, you can write something like
144 `arch.RPI='arm-unknown-linux-gnueabihf'`. Then `nailing-cargo -ARPI`
145 will DTRT. In fact, you do not even need to specify that particular
146 arch alias, since it is built-in to nailing-cargo.
148 Default change to offline mode
149 ==============================
151 It seems to me that build tools should be explicit about their use of
152 the network. So by default, nailing-cargo passes `--offline` to
155 If you disagree with my opinion, write `misc.online=true` in your
156 nailing-cargo configuration. `misc.online=false`, and command line
157 options, are also available, for overriding.
159 Invocation and command-line option reference
160 ============================================
166 1$ nailing-cargo <nailing-opts> <cargo-opts> [--] <subcmd>...
167 2$ nailing-cargo <nailing-opts> --- <cargo> <cargo-opts> [--] <subcmd>...
168 3$ nailing-cargo <nailing-opts> --- [--] <build-command>...
170 Ususally the `--` is not needed. (It should generally be passed by
171 programs which wrap nailing-cargo. See below.)
173 In usage 1, nailing-cargo runs `cargo` (from `PATH`). In the usage 2
174 nailing-cargo runs `<cargo>`. In both these cases it adds its own
175 options to control cargo's behaviour. In both of these cases
176 nailing-cargo looks at `<subcmd>` to determine the cargo subcommand
177 being run: this controls various defaults, to try to do the right
180 In the third syntax, nailing-cargo runs `<build-command>...` without
181 additional arguments and does not attempt to identify the cargo
182 subcommand(s) that it will run. Possibly it will be necessary to pass
183 `--online` or `--cargo-lock-update`, or even `--cargo-*arg*`
185 ### Invocation argument disambiguation rules ###
187 For authors of tools which call nailing-cargo (and pedants):
189 The usages overlap in syntax! nailing-cargo follows the following
190 rules when interpreting its command line:
192 * The first option not recognised as a nailing-cargo option is
193 treated as the start of the `<cargo-opts>`.
195 * `<cargo-opts>` are terminated by `--` (which is removed) or the
196 first argument which does not start with a `-`.
198 (It is not possible to get nailing-cargo to pass the value `--`
199 as a separate argument to a cargo global option, but cargo global
200 options can typically take the values cuddled with `=`, so doing
201 that is not necessary.)
203 * After `---`, nailing-cargo will search for a `--`, to the end of
204 the arguments if necessary. The position of the `--` determines
205 whether this is usage 2 or usage 3, and what `<subcmd>` is.
207 If the arguments after `nailing-cargo ... ---` might contain `--`
208 anywhere, an explicit `--` should be passed.
210 * If no `--` appears after `---`, the word after `---` is the
211 command to run; if its final pathname component contains the
212 string `cargo`, it is treated as `<cargo>` (implying usage 2 and
213 the search for `<subcmd>`). Otherwise it is treated as
214 `<build-command>` (usage 3).
219 * `-v`: Increase verbosity. Default is 1.
221 * `-q`: Set verbosity to 0.
223 * `-D`: Increase amount of debugging dump.
225 * `-n`: "No action": stop after writing `Cargo.toml.nailing~`
226 everywhere, and do not run any build command.
228 * `-A<arch>` | `--arch=<arch>` | `--target=<arch>`
230 Specify target architecture.
232 This option translates to a `--target=<arch>` option to the
233 ultimate command, unless that is a cargo subcommand which we
234 know would reject it. `--arch` and `--target` are simply
237 If `<arch>` starts with a capital ascii letter, it is an alias
238 for some other arch: it is looked up in the configuration, and
239 then in the builtin arch alias list. The builtin list is
240 equivalent to: `[arch]` `RPI='arm-unknown-linux-gnueabihf'`.
242 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
244 Enables, or disables, the dance to allow `Cargo.lock` (or
245 alternative) to be updated in the source directory.
247 With this dance enabled the `Cargo.lock` and `Cargo.toml` are
248 copied to the build directory along with a skeleton just big
249 enough to fool cargo. After cargo has run, the resulting
250 `Cargo.lock` is copied back to the source tree.
252 This makes no sense with in-tree builds.
254 Default is no update unless the ultimate command is a
255 cargo subcommand which we know needs it.
257 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
259 Controls whether we add cargo command line options, relating to
260 finding `Cargo.toml`, to the command to run.
262 Default is to add them if we are doing an out-of-tree build,
263 unless we are doing the dance to update the `Cargo.lock` (see
264 above) since in that case all the relevant files can be found
265 by cargo in the build directory.
267 The arguments added are
269 --manifest-path=<path/to/Cargo.toml>
273 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
275 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
276 makes any difference with `-m`, since otherwise no
277 `--target-dir` would be passed anyway. Additionally this is
278 done automatically when nailing-cargo sees that the cargo
279 subcommand is one which needs it, eg `fetch`.
281 * `-o` | `--online` | `-O` | `--offline`
283 Whether to allow cargo to make network access. nailing-cargo
284 always passes `--offline` to cargo, unless `--online` is in
285 force. The default value depends on the configuration and the
286 cargo subcommand - see `[misc]` `online` in "Configuration".
288 Environment of the build command
289 --------------------------------
291 nailing-cargo passes these environment variables to the build command:
293 * `NAILINGCARGO_WORKSPHERE`: invocation `..` (parent)
294 * `NAILINGCARGO_MANIFEST_DIR`: invocation `.` (invocation directory)
295 * `NAILINGCARGO_BUILD_DIR`: build directory (even if same as source)
296 * `NAILINGCARGO_BUILDSPHERE`: only set if out of tree: parent of build dir.
298 All of these are absolute paths.
300 Configuration reference
301 =======================
303 nailing-cargo reads these configuration files:
305 /etc/nailing-cargo/cfg.toml
306 ~/.nailing-cargo.toml
307 ./.nailing-cargo.toml
308 ../Nailing-Cargo.toml
311 Settings in later-mentioned files override ones in earlier-mentioned
314 Source directories and packages (toplevel)
315 ------------------------------------------
317 Note that unlike everything else, these keys (`packages` and
318 `subdirs`) are read only from `Cargo.nail` (see "Limitations and
321 These keys specify a combination of (i) a mapping from package name to
322 source subdirectory (ii) a set of subdirectories whose `Cargo.toml`
325 * `packages`: a map keyed by package name, giving the subdirectory
328 This causes each mentioned subdirectory's `Cargo.toml` to be
329 massaged, and records that subdirectory as the source for that
330 package. (nailing-cargo will check that subdirectory actually
331 contains the indicated package.)
333 Each value can be just the subdirectory name (eg `[packages]`
334 `mylibrary='mylibrary-test'`) or itself a map with the key `subdir`
335 (eg `[packages.mylibrary]` `subdir='mylibrary-test'`).
337 * `subdirs`: a list of subdirectory names to process.
339 Each subdirectory's `Cargo.toml` will be massaged. Also, the
340 subdirectory will be examined to see what package it contains; it
341 will then be used as the source for that package, unless that
342 package appears in an entry in `packages`, or an earlier entry in
345 This can be a list of strings (eg `subdirs =
346 ['myproject','mylibrary']`). Or it can be single multi-line
347 string containing one subdirectory name per line; in that
348 case, `#`-comments are supported and tabs and spaces are ignored
349 (see "Most basic example usage" above.)
351 In each case the subdirectory should usually be a relative pathname;
352 it is relative to the directory containing `Cargo.nail`.
354 `[alt_cargolock]`: Alternative `Cargo.lock` filename
355 ----------------------------------------------------
357 To control use of alternative `Cargo.lock` filename, use the section
358 `[alt_cargolock]`. Settings here:
360 * `file = <some leafname>`.
362 * `file = true`: Equivalent to `file = "Cargo.lock.example"`.
363 (This is the default.)
365 * `file = false`: Disables this feature.
367 * `force = false`: Uses the alternative filename only if it
368 already exists. (This is the default.)
370 * `force = true`: Always uses the alternative filename.
372 `[oot]`: Out-of-tree build support
373 ----------------------------------
375 * `dir`: The build directory. If relative, it is relative to the
376 parent of the invocation directory (and could be a symlink then).
377 Default is `Build` (assuming `use` is specified).
379 The build directory will contain one subdir for each package: each
380 subdir in the build dir corresponds to one source dir where
381 nailing-cargo was invoked. nailing-cargo will arrange to create
382 these subdirectories, so the build directory can start out empty.
384 * `use`: How to become the build user. Needs to be combined
385 with other setting(s):
387 * `ssh`: Use ssh. `user` must be given as well and can be
388 a username on localhost, or the `<user>@<host>`
391 * `command_args`: `command` must be specified as a list,
392 specifying a command and arguments which work like `nice`.
394 * `command_sh`: `command` must be specified as a list,
395 specifying a command and arguments which work like `sh -c`.
397 * `null`: Run builds as the same user.
399 * `really`: Use `really` from `chiark-really.deb`.
400 `user` must be given as well.
402 * `command`: The command to run for `command_sh` or `command_args`.
404 * `user`: The local username for `really` and `ssh`, or
405 `<user>@<host>` for `ssh`.
407 `[arch]`: Architecture convenience aliases
408 ------------------------------------------
410 This is a map from archictecture aliases to full cargo architecture
411 names. The keys are the aliases; each entry should be a string, the
412 cargo architecture name.
414 Only keys starting with an ascii uppercase letter are relevant, since
415 other names are not looked up in this alias map.
417 `[misc]`: Miscellaneous individual nailing-cargo config
418 -------------------------------------------------------
420 * `online`: boolean, specifying whether to pass `--offline` to cargo
421 (cargo's default is online mode). The default is offline, unless
422 nailing-cargo can see that the cargo subcommand being invoked is
423 one which requires online access (currently, `fetch`), in which
424 case the default is online.
429 * nailing-cargo temporarily dirties your source trees, including
430 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
431 crashes or is interrupted these changes may be left behind.
432 Unfortunately it is not possible to avoid this temporary dirtying
433 because the cargo team have deliberately made cargo inflexible -
434 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
435 At least, running nailing-cargo again will clean up any mess
436 left by an interrupted run.
438 * Out of tree builds require a unified filesystem view: eg, different
439 users on the same host, NFS, or something.
441 Specifically, the invocation and build execution environments must
442 both have visibility of the source and build directories, at the
443 same absolute pathnames. The invocation environment must be able
444 to write to the build environment (but vice versa is not
447 This could be improved.
449 * The alternative `Cargo.lock` filename must currently be a leafname. I
450 think fixing this just involves review to check other values work
453 * The alternative `Cargo.lock` file must be on the same filesystem
454 as the source tree. This is not so easy to fix; we would want the
455 existing algorithm but a fallback for the different-filsystem case.
457 * `Cargo.nail` is unconditionally looked for in the parent directory.
458 Ideally this should be configurable, and also perhaps be able to
459 combine multiple `Cargo.nail` files? Relatedly, although
460 nailing-cargo can read multiple config files, it can only handle
461 one file specifying directories and packages.
463 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
464 rather than a more sophisticated scheme involving locking
465 particular directories. This means that if you run multiple
466 copies of nailing-cargo at once, in different directories, but
467 with `Cargo.nail` files which imply overlapping sets of package
468 directories, things will go Badly Wrong.
470 Contributing and legal
471 ======================
473 nailing-cargo is Free Software.
475 Please help improve it. Contributions (to address the limitations, or
476 to add new facilities to help work with cargo) are welcome by email to
477 `ijackson@chiark.greenend.org.uk` or via the [Salsa
478 project](https://salsa.debian.org/iwj/nailing-cargo).
480 If you plan to do substantial work, please do get in touch with a
481 sketch of your proposed changes.
486 This project accepts contributions based on the git commit
487 Signed-off-by convention, by which the contributors certify their
488 contributions according to the Developer Certificate of Origin version
489 1.1 - see the file DEVELOPER-CERTIFICATE.
491 Copyright (C) 2019-2020 Ian Jackson and others
493 This program is free software: you can redistribute it and/or modify
494 it under the terms of the GNU Affero General Public License as
495 published by the Free Software Foundation, either version 3 of the
496 License, or (at your option) any later version.
498 This program is distributed in the hope that it will be useful,
499 but WITHOUT ANY WARRANTY; without even the implied warranty of
500 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
501 GNU Affero General Public License for more details.
503 You should have received a copy of the GNU Affero General Public License
504 along with this program. If not, see <http://www.gnu.org/licenses/>.
506 Individual files generally contain the following tag in the copyright
507 notice, instead of the full licence grant text:
509 SPDX-License-Identifier: AGPL-3.0-or-later
511 As is conventional, this should be read as a licence grant.