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56 especially completely unpublished ones.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58 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),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 The primary config keys here are:
120 * `dir`: The build directory. If relative, it is relative to the
121 parent of the invocation directory (and could be a symlink then).
122 Default is `Build` (assuming `use` is specified).
124 * `use`: How to become the build user. Needs to be combined
125 with other setting(s):
127 * `ssh`: Use ssh. `user` must be given as well and can be
128 a username on localhost, or the `<user>@<host>`
131 * `command_args`: `command` must be specified as a list,
132 specifying a command and arguments which work like `nice`.
134 * `command_sh`: `command` must be specified as a list,
135 specifying a command and arguments which work like `sh -c`.
137 * `null`: Run builds as the same user.
139 * `really`: Use `really` from `chiark-really.deb`.
140 `user` must be given as well.
142 Target architecture convenience aliases
143 =======================================
145 If you are cross-building you may need to tell cargo `--target=`.
146 The architecture names are quite long and inconvenient.
148 A simple shell alias would help a lot, except that cargo rejects
149 `--target=` when it thinks it's not needed.
151 In your nailing-cargo config, you can write something like
152 `arch.RPI='arm-unknown-linux-gnueabihf'`. Then `nailing-cargo -ARPI`
153 will DTRT. In fact, you do not even need to specify that particular
154 arch alias, since it is built-in to nailing-cargo.
156 Default change to offline mode
157 ==============================
159 It seems to me that build tools should be explicit about their use of
160 the network. So by default, nailing-cargo passes `--offline` to
163 If you disagree with my opinion, write `misc.online=true` in your
164 nailing-cargo configuration. `misc.online=false`, and command line
165 options, are also available, for overriding.
170 * `-v`: Increase verbosity. Default is 1.
172 * `-q`: Set verbosity to 0.
174 * `-D`: Increase amount of debugging dump.
176 * `-n`: "No action": stop after writing `Cargo.toml.nailing~`
177 everywhere, and do not run any build command.
179 * `-A<arch>` | `--arch=<arch>` | `--target=<arch>`
181 Specify target architecture.
183 This option translates to a `--target=<arch>` option to the
184 ultimate command, unless that is a cargo subcommand which we
185 know would reject it. `--arch` and `--target` are simply
188 If `<arch>` starts with a capital ascii letter, it is an alias
189 for some other arch: it is looked up in the configuration, and
190 then in the builtin arch alias list. The builtin list is
191 equivalent to: `[arch]` `RPI='arm-unknown-linux-gnueabihf'`.
193 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
195 Enables, or disables, the dance to allow `Cargo.lock` (or
196 alternative) to be updated in the source directory.
198 With this dance enabled the `Cargo.lock` and `Cargo.toml` are
199 copied to the build directory along with a skeleton just big
200 enough to fool cargo. After cargo has run, the resulting
201 `Cargo.lock` is copied back to the source tree.
203 This makes no sense with in-tree builds.
205 Default is no update unless the ultimate command is a
206 cargo subcommand which we know needs it.
208 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
210 Controls whether we add cargo command line options, relating to
211 finding `Cargo.toml`, to the command to run.
213 Default is to add them if we are doing an out-of-tree build,
214 unless we are doing the dance to update the `Cargo.lock` (see
215 above) since in that case all the relevant files can be found
216 by cargo in the build directory.
218 The arguments added are
220 --manifest-path=<path/to/Cargo.toml>
224 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
226 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
227 makes any difference with `-m`, since otherwise no
228 `--target-dir` would be passed anyway. Additionally this is
229 done automatically when nailing-cargo sees that the cargo
230 subcommand is one which needs it, eg `fetch`.
232 * `-o` | `--online` | `-O` | `--offline`
234 Whether to allow cargo to make network access. nailing-cargo
235 always passes `--offline` to cargo, unless `--online` is in
236 force. The default is offline, unless the cargo subcommand is
237 one which implies online (currently, `fetch`).
242 nailing-cargo reads these configuration files:
244 /etc/nailing-cargo/cfg.toml
245 ~/.nailing-cargo.toml
246 ./.nailing-cargo.toml
247 ../Nailing-Cargo.toml
250 Settings in later-mentioned files override ones in earlier-mentioned
253 Source directories and packages (toplevel)
254 ------------------------------------------
256 Note that unlike everything else, these keys `packages` and `subdirs`
257 are read only from `Cargo.nail` (see "Limitations and bugs", below).
259 These keys specify a combination of (i) a mapping from package name to
260 source subdirectory (ii) a set of subdirectories whose `Cargo.toml`
263 * `packages`: a map keyed by package name, giving the subdirectory
266 This causes each mentioned subdirectory's `Cargo.toml` to be
267 massaged, and records that subdirectory as the source for that
268 package. (nailing-cargo will check that subdirectory actually
269 contains the indicated package.)
271 Each value can be just the subdirectory name (eg `[packages]`
272 `mylibrary='mylibrary-test'`) or itself a map with the key `subdir`
273 (eg `[packages.mylibrary]` `subdir='mylibrary-test'`).
275 * `subdirs`: a list of subdirectory names to process.
277 Each subdirectory's `Cargo.toml` will be massaged; also, the
278 subdirectory will be examined to see what package it contains and
279 it will be used as the source for that package, unless that
280 package appears in an entry in `packages`, or an earlier entry in
283 This can be a list of strings (eg `subdirs =
284 ['myproject','mylibrary']`). Or it can be single multi-line
285 string containing one subdirectory name per line; in that
286 case, `#`-comments are supported and tabs and spaces are ignored
287 (See "Most basic example usage" above.)
289 In each case the subdirectory should usually be a relative pathname;
290 it is relative to the directory containing `Cargo.nail`.
292 `[alt_cargolock]`: Alternative `Cargo.lock` filename
293 ----------------------------------------------------
295 To control use of alternative `Cargo.lock` filename, use the section
296 `[alt_cargolock]`. Settings here:
298 * `file = <some leafname>`.
300 * `file = true`: Equivalent to `file = "Cargo.lock.example"`.
301 (This is the default.)
303 * `file = false`: Disables this feature.
305 * `force = false`: Uses the alternative filename only if it
306 already exists. (This is the default.)
308 * `force = true`: Always uses the alternative filename.
313 Normally you pass cargo as an argument to nailing-cargo. But you
314 can also pass make or any other command. You may need to pass
315 `--no-cargo-manifest-args` (aka `-M`) to nailing-cargo, to avoid
316 passing options like `--manifest-path` to make or whatever.
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.
330 * nailing-cargo temporarily dirties your source trees, including
331 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
332 crashes or is interrupted these changes may be left behind.
333 Unfortunately it is not possible to avoid this temporary dirtying
334 because the cargo team have deliberately made cargo inflexible -
335 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
336 At least, running nailing-cargo again will clean up any mess
337 left by an interrupted run.
339 * Out of tree builds require a unified filesystem view: eg, different
340 users on the same host, NFS, or something.
342 Specifically, the invocation and build execution environments must
343 both have visibility of the source and build directories, at the
344 same absolute pathnames. The invocation environment must be able
345 to write to the build environment (but vice versa is not
348 This could be improved.
350 * The alternative `Cargo.lock` filename must currently be a leafname. I
351 think fixing this just involves review to check other values work
354 * The alternative `Cargo.lock` file must be on the same filesystem
355 as the source tree. This is not so easy to fix; we would want the
356 existing algorithm but a fallback for the different-filsystem case.
358 * `Cargo.nail` is unconditionally looked for in the parent directory.
359 Ideally this should be configurable, and also perhaps be able to
360 combine multiple `Cargo.nail` files? Relatedly, although
361 nailing-cargo can read multiple config files, it can only handle
362 one file specifying directories and packages.
364 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
365 rather than a more sophisticated scheme involving locking
366 particular directories. This means that if you run multiple
367 copies of nailing-cargo at once, in different directories, but
368 with `Cargo.nail` files which imply overlapping sets of package
369 directories, things will go Badly Wrong.
371 Contributing and legal
372 ======================
374 nailing-cargo is Free Software.
376 Please help improve it. Contributions (to address the limitations, or
377 to add new facilities to help work with cargo) are welcome by email to
378 `ijackson@chiark.greenend.org.uk` or via the [Salsa
379 project](https://salsa.debian.org/iwj/nailing-cargo).
381 If you plan to do substantial work, please do get in touch with a
382 sketch of your proposed changes.
387 This project accepts contributions based on the git commit
388 Signed-off-by convention, by which the contributors certify their
389 contributions according to the Developer Certificate of Origin version
390 1.1 - see the file DEVELOPER-CERTIFICATE.
392 Copyright (C) 2019-2020 Ian Jackson and others
394 This program is free software: you can redistribute it and/or modify
395 it under the terms of the GNU Affero General Public License as
396 published by the Free Software Foundation, either version 3 of the
397 License, or (at your option) any later version.
399 This program is distributed in the hope that it will be useful,
400 but WITHOUT ANY WARRANTY; without even the implied warranty of
401 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
402 GNU Affero General Public License for more details.
404 You should have received a copy of the GNU Affero General Public License
405 along with this program. If not, see <http://www.gnu.org/licenses/>.
407 Individual files generally contain the following tag in the copyright
408 notice, instead of the full licence grant text:
410 SPDX-License-Identifier: AGPL-3.0-or-later
412 As is conventional, this should be read as a licence grant.