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 -------------------------------
55 <!-- TOC autogenerated by ./markdown-toc-filter, do not edit -->
57 * [Introduction](#nailing-cargo)
58 * [Installing](#installing)
59 * [Most basic example usage](#most-basic-example-usage)
60 * [Documentation table of contents](#documentation-table-of-contents)
61 * [Using local crates, or locally modified crates](#using-local-crates-or-locally-modified-crates)
62 * [How nailing-cargo helps with using local crates](#how-nailing-cargo-helps-with-using-local-crates)
63 * [Telling nailing-cargo how to massage `Cargo.toml`](#telling-nailing-cargo-how-to-massage-cargo.toml)
64 * [Out-of-tree builds](#out-of-tree-builds)
65 * [How nailing-cargo helps with out-of-tree builds](#how-nailing-cargo-helps-with-out-of-tree-builds)
66 * [Configuring out-of-tree builds](#configuring-out-of-tree-builds)
67 * [Target architecture convenience aliases](#target-architecture-convenience-aliases)
68 * [Default change to offline mode](#default-change-to-offline-mode)
69 * [Invocation and command-line option reference](#invocation-and-command-line-option-reference)
72 * [Environment of the build command](#environment-of-the-build-command)
73 * [Configuration reference](#configuration-reference)
74 * [Source directories and packages (toplevel)](#source-directories-and-packages-toplevel)
75 * [`[alt_cargolock]`: Alternative `Cargo.lock` filename](#alt_cargolock-alternative-cargo.lock-filename)
76 * [`[oot]`: Out-of-tree build support](#oot-out-of-tree-build-support)
77 * [`[arch]`: Architecture convenience aliases](#arch-architecture-convenience-aliases)
78 * [`[misc]`: Miscellaneous individual nailing-cargo config](#misc-miscellaneous-individual-nailing-cargo-config)
79 * [Limitations and bugs](#limitations-and-bugs)
80 * [Contributing and legal](#contributing-and-legal)
83 Using local crates, or locally modified crates
84 ==============================================
86 cargo does not work well with local crates,
87 especially completely unpublished ones.
88 (See [issue#6713](https://github.com/rust-lang/cargo/issues/6713),
89 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),
90 [issue#1481](https://github.com/rust-lang/cargo/issues/1481),
91 [my blog](https://diziet.dreamwidth.org/1805.html).)
93 Using a local version of a crate should be possible without putting
94 paths into your `Cargo.toml` and without editing complex
97 How nailing-cargo helps with using local crates
98 -----------------------------------------------
100 nailing-cargo temporarily edits all the `Cargo.toml` files in all the
101 subdirectories you mention, to refer to each other; then it runs
102 cargo; and then it puts everything back.
104 Telling nailing-cargo how to massage `Cargo.toml`
105 -------------------------------------------------
107 To find the subdirectories, and the packages, it looks for `subdirs`
108 and `packages` in `Cargo.nail`.
110 For straightforward use, write `subdirs` as a multi-line string
111 containing a list of subdirectory names one per line. In each of
112 these directories `Cargo.toml` will be massaged, and the package there
113 will be used for other massaged `Cargo.toml`s.
115 See "Configuration reference", below, for full details.
120 It is often desirable to run builds in a way that does not write to
121 the source tree. cargo's enthusiastic approach to the dependency
122 management task means that it is a good idea to try to insulate your
123 main working environment from the many things cargo has decided to
124 download and execute.
126 However, when you tell cargo to do an out of tree build (using
127 `--manifest-path`) it will insist on `Cargo.lock` being in the source
128 directory, and often will insist on writing to it.
130 How nailing-cargo helps with out-of-tree builds
131 -----------------------------------------------
133 nailing-cargo (configured appropriately) copies files back and forth
134 to between the source and build directories, and runs cargo as your
137 The `Cargo.lock` must still be saved in your source tree somewhere.
138 nailing-cargo arranges this for you. You can either put this file in
139 `.gitignore`; or commit it to git; or you can tell nailing-cargo to
140 save it as something like `Cargo.lock.example`.
142 Configuring out-of-tree builds
143 ------------------------------
145 To enable out-of-tree-builds, put an `[oot]` section in your
146 `Cargo.nail` or one of nailing-cargo's other config files.
147 In that section, specify at least `use`.
149 Also, specify `dir`, or create a symlink `Build` next to `Cargo.nail`,
150 pointing to to your build area.
158 will have nailing-cargo run `ssh rustcargo@localhost` to
161 Target architecture convenience aliases
162 =======================================
164 If you are cross-building you may need to tell cargo `--target=`.
165 The architecture names are quite long and inconvenient.
167 A simple shell alias would help a lot, except that cargo rejects
168 `--target=` when it thinks it's not needed.
170 In your nailing-cargo config, you can write something like
171 `arch.RPI='arm-unknown-linux-gnueabihf'`. Then `nailing-cargo -ARPI`
172 will DTRT. In fact, you do not even need to specify that particular
173 arch alias, since it is built-in to nailing-cargo.
175 Default change to offline mode
176 ==============================
178 It seems to me that build tools should be explicit about their use of
179 the network. So by default, nailing-cargo passes `--offline` to
182 If you disagree with my opinion, write `misc.online=true` in your
183 nailing-cargo configuration. `misc.online=false`, and command line
184 options, are also available, for overriding.
186 Invocation and command-line option reference
187 ============================================
193 1$ nailing-cargo <nailing-opts> <cargo-opts> [--] <subcmd>...
194 2$ nailing-cargo <nailing-opts> --- <cargo> <cargo-opts> [--] <subcmd>...
195 3$ nailing-cargo <nailing-opts> --- [--] <build-command>...
197 Ususally the `--` is not needed. (It should generally be passed by
198 programs which wrap nailing-cargo. See below.)
200 In usage 1, nailing-cargo runs `cargo` (from `PATH`). In the usage 2
201 nailing-cargo runs `<cargo>`. In both these cases it adds its own
202 options to control cargo's behaviour. In both of these cases
203 nailing-cargo looks at `<subcmd>` to determine the cargo subcommand
204 being run: this controls various defaults, to try to do the right
207 In the third syntax, nailing-cargo runs `<build-command>...` without
208 additional arguments and does not attempt to identify the cargo
209 subcommand(s) that it will run. Possibly it will be necessary to pass
210 `--online` or `--cargo-lock-update`, or even `--cargo-*arg*`
212 ### Invocation argument disambiguation rules ###
214 For authors of tools which call nailing-cargo (and pedants):
216 The usages overlap in syntax! nailing-cargo follows the following
217 rules when interpreting its command line:
219 * The first option not recognised as a nailing-cargo option is
220 treated as the start of the `<cargo-opts>`.
222 * `<cargo-opts>` are terminated by `--` (which is removed) or the
223 first argument which does not start with a `-`.
225 (It is not possible to get nailing-cargo to pass the value `--`
226 as a separate argument to a cargo global option, but cargo global
227 options can typically take the values cuddled with `=`, so doing
228 that is not necessary.)
230 * After `---`, nailing-cargo will search for a `--`, to the end of
231 the arguments if necessary. The position of the `--` determines
232 whether this is usage 2 or usage 3, and what `<subcmd>` is.
234 If the arguments after `nailing-cargo ... ---` might contain `--`
235 anywhere, an explicit `--` should be passed.
237 * If no `--` appears after `---`, the word after `---` is the
238 command to run; if its final pathname component contains the
239 string `cargo`, it is treated as `<cargo>` (implying usage 2 and
240 the search for `<subcmd>`). Otherwise it is treated as
241 `<build-command>` (usage 3).
246 * `-v`: Increase verbosity. Default is 1.
248 * `-q`: Set verbosity to 0.
250 * `-D`: Increase amount of debugging dump.
252 * `-n`: "No action": stop after writing `Cargo.toml.nailing~`
253 everywhere, and do not run any build command.
255 * `-A<arch>` | `--arch=<arch>` | `--target=<arch>`
257 Specify target architecture.
259 This option translates to a `--target=<arch>` option to the
260 ultimate command, unless that is a cargo subcommand which we
261 know would reject it. `--arch` and `--target` are simply
264 If `<arch>` starts with a capital ascii letter, it is an alias
265 for some other arch: it is looked up in the configuration, and
266 then in the builtin arch alias list. The builtin list is
267 equivalent to: `[arch]` `RPI='arm-unknown-linux-gnueabihf'`.
269 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
271 Enables, or disables, the dance to allow `Cargo.lock` (or
272 alternative) to be updated in the source directory.
274 With this dance enabled the `Cargo.lock` and `Cargo.toml` are
275 copied to the build directory along with a skeleton just big
276 enough to fool cargo. After cargo has run, the resulting
277 `Cargo.lock` is copied back to the source tree.
279 This makes no sense with in-tree builds.
281 Default is no update unless the ultimate command is a
282 cargo subcommand which we know needs it.
284 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
286 Controls whether we add cargo command line options, relating to
287 finding `Cargo.toml`, to the command to run.
289 Default is to add them if we are doing an out-of-tree build,
290 unless we are doing the dance to update the `Cargo.lock` (see
291 above) since in that case all the relevant files can be found
292 by cargo in the build directory.
294 The arguments added are
296 --manifest-path=<path/to/Cargo.toml>
300 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
302 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
303 makes any difference with `-m`, since otherwise no
304 `--target-dir` would be passed anyway. Additionally this is
305 done automatically when nailing-cargo sees that the cargo
306 subcommand is one which needs it, eg `fetch`.
308 * `-o` | `--online` | `-O` | `--offline`
310 Whether to allow cargo to make network access. nailing-cargo
311 always passes `--offline` to cargo, unless `--online` is in
312 force. The default value depends on the configuration and the
313 cargo subcommand - see `[misc]` `online` in "Configuration".
315 Environment of the build command
316 --------------------------------
318 nailing-cargo passes these environment variables to the build command:
320 * `NAILINGCARGO_WORKSPHERE`: invocation `..` (parent)
321 * `NAILINGCARGO_MANIFEST_DIR`: invocation `.` (invocation directory)
322 * `NAILINGCARGO_BUILD_DIR`: build directory (even if same as source)
323 * `NAILINGCARGO_BUILDSPHERE`: only set if out of tree: parent of build dir.
325 All of these are absolute paths.
327 Configuration reference
328 =======================
330 nailing-cargo reads these configuration files:
332 /etc/nailing-cargo/cfg.toml
333 ~/.nailing-cargo.toml
334 ./.nailing-cargo.toml
335 ../Nailing-Cargo.toml
338 Settings in later-mentioned files override ones in earlier-mentioned
341 Source directories and packages (toplevel)
342 ------------------------------------------
344 Note that unlike everything else, these keys (`packages` and
345 `subdirs`) are read only from `Cargo.nail` (see "Limitations and
348 These keys specify a combination of (i) a mapping from package name to
349 source subdirectory (ii) a set of subdirectories whose `Cargo.toml`
352 * `packages`: a map keyed by package name, giving the subdirectory
355 This causes each mentioned subdirectory's `Cargo.toml` to be
356 massaged, and records that subdirectory as the source for that
357 package. (nailing-cargo will check that subdirectory actually
358 contains the indicated package.)
360 Each value can be just the subdirectory name (eg `[packages]`
361 `mylibrary='mylibrary-test'`) or itself a map with the key `subdir`
362 (eg `[packages.mylibrary]` `subdir='mylibrary-test'`).
364 * `subdirs`: a list of subdirectory names to process.
366 Each subdirectory's `Cargo.toml` will be massaged. Also, the
367 subdirectory will be examined to see what package it contains; it
368 will then be used as the source for that package, unless that
369 package appears in an entry in `packages`, or an earlier entry in
372 This can be a list of strings (eg `subdirs =
373 ['myproject','mylibrary']`). Or it can be single multi-line
374 string containing one subdirectory name per line; in that
375 case, `#`-comments are supported and tabs and spaces are ignored
376 (see "Most basic example usage" above.)
378 In each case the subdirectory should usually be a relative pathname;
379 it is relative to the directory containing `Cargo.nail`.
381 `[alt_cargolock]`: Alternative `Cargo.lock` filename
382 ----------------------------------------------------
384 To control use of alternative `Cargo.lock` filename, use the section
385 `[alt_cargolock]`. Settings here:
387 * `file = <some leafname>`.
389 * `file = true`: Equivalent to `file = "Cargo.lock.example"`.
390 (This is the default.)
392 * `file = false`: Disables this feature.
394 * `force = false`: Uses the alternative filename only if it
395 already exists. (This is the default.)
397 * `force = true`: Always uses the alternative filename.
399 `[oot]`: Out-of-tree build support
400 ----------------------------------
402 * `dir`: The build directory. If relative, it is relative to the
403 parent of the invocation directory (and could be a symlink then).
404 Default is `Build` (assuming `use` is specified).
406 The build directory will contain one subdir for each package: each
407 subdir in the build dir corresponds to one source dir where
408 nailing-cargo was invoked. nailing-cargo will arrange to create
409 these subdirectories, so the build directory can start out empty.
411 * `use`: How to become the build user. Needs to be combined
412 with other setting(s):
414 * `ssh`: Use ssh. `user` must be given as well and can be
415 a username on localhost, or the `<user>@<host>`
418 * `command_args`: `command` must be specified as a list,
419 specifying a command and arguments which work like `nice`.
421 * `command_sh`: `command` must be specified as a list,
422 specifying a command and arguments which work like `sh -c`.
424 * `null`: Run builds as the same user.
426 * `really`: Use `really` from `chiark-really.deb`.
427 `user` must be given as well.
429 * `command`: The command to run for `command_sh` or `command_args`.
431 * `user`: The local username for `really` and `ssh`, or
432 `<user>@<host>` for `ssh`.
434 `[arch]`: Architecture convenience aliases
435 ------------------------------------------
437 This is a map from archictecture aliases to full cargo architecture
438 names. The keys are the aliases; each entry should be a string, the
439 cargo architecture name.
441 Only keys starting with an ascii uppercase letter are relevant, since
442 other names are not looked up in this alias map.
444 `[misc]`: Miscellaneous individual nailing-cargo config
445 -------------------------------------------------------
447 * `online`: boolean, specifying whether to pass `--offline` to cargo
448 (cargo's default is online mode). The default is offline, unless
449 nailing-cargo can see that the cargo subcommand being invoked is
450 one which requires online access (currently, `fetch`), in which
451 case the default is online.
456 * nailing-cargo temporarily dirties your source trees, including
457 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
458 crashes or is interrupted these changes may be left behind.
459 Unfortunately it is not possible to avoid this temporary dirtying
460 because the cargo team have deliberately made cargo inflexible -
461 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
462 At least, running nailing-cargo again will clean up any mess
463 left by an interrupted run.
465 * Out of tree builds require a unified filesystem view: eg, different
466 users on the same host, NFS, or something.
468 Specifically, the invocation and build execution environments must
469 both have visibility of the source and build directories, at the
470 same absolute pathnames. The invocation environment must be able
471 to write to the build environment (but vice versa is not
474 This could be improved.
476 * The alternative `Cargo.lock` filename must currently be a leafname. I
477 think fixing this just involves review to check other values work
480 * The alternative `Cargo.lock` file must be on the same filesystem
481 as the source tree. This is not so easy to fix; we would want the
482 existing algorithm but a fallback for the different-filsystem case.
484 * `Cargo.nail` is unconditionally looked for in the parent directory.
485 Ideally this should be configurable, and also perhaps be able to
486 combine multiple `Cargo.nail` files? Relatedly, although
487 nailing-cargo can read multiple config files, it can only handle
488 one file specifying directories and packages.
490 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
491 rather than a more sophisticated scheme involving locking
492 particular directories. This means that if you run multiple
493 copies of nailing-cargo at once, in different directories, but
494 with `Cargo.nail` files which imply overlapping sets of package
495 directories, things will go Badly Wrong.
497 Contributing and legal
498 ======================
500 nailing-cargo is Free Software.
502 Please help improve it. Contributions (to address the limitations, or
503 to add new facilities to help work with cargo) are welcome by email to
504 `ijackson@chiark.greenend.org.uk` or via the [Salsa
505 project](https://salsa.debian.org/iwj/nailing-cargo).
507 If you plan to do substantial work, please do get in touch with a
508 sketch of your proposed changes.
513 This project accepts contributions based on the git commit
514 Signed-off-by convention, by which the contributors certify their
515 contributions according to the Developer Certificate of Origin version
516 1.1 - see the file DEVELOPER-CERTIFICATE.
518 Copyright (C) 2019-2020 Ian Jackson and others
520 This program is free software: you can redistribute it and/or modify
521 it under the terms of the GNU Affero General Public License as
522 published by the Free Software Foundation, either version 3 of the
523 License, or (at your option) any later version.
525 This program is distributed in the hope that it will be useful,
526 but WITHOUT ANY WARRANTY; without even the implied warranty of
527 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
528 GNU Affero General Public License for more details.
530 You should have received a copy of the GNU Affero General Public License
531 along with this program. If not, see <http://www.gnu.org/licenses/>.
533 Individual files generally contain the following tag in the copyright
534 notice, instead of the full licence grant text:
536 SPDX-License-Identifier: AGPL-3.0-or-later
538 As is conventional, this should be read as a licence grant.