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56 especially completely unpublished ones.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58 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),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 `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). These subdirectories are also added to the list
91 of places 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.
189 This option translates to a `--target=<arch>` option to the
190 ultimate command, unless that is a cargo subcommand which we
191 know would reject it. `--arch` and `--target` are simply
194 If `<arch>` starts with a capital ascii letter, it is an alias
195 for some other arch: it is looked up in the configuration, and
196 then in the builtin arch alias list. The builtin list is
197 equivalent to: `[arch]` `RPI='arm-unknown-linux-gnueabihf'`.
199 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
201 Enables, or disables, the dance to allow `Cargo.lock` (or
202 alternative) to be updated in the source directory.
204 With this dance enabled the `Cargo.lock` and `Cargo.toml` are
205 copied to the build directory along with a skeleton just big
206 enough to fool cargo. After cargo has run, the resulting
207 `Cargo.lock` is copied back to the source tree.
209 This makes no sense with in-tree builds.
211 Default is no update unless the ultimate command is a
212 cargo subcommand which we know needs it.
214 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
216 Controls whether we add cargo command line options, relating to
217 finding `Cargo.toml`, to the command to run.
219 Default is to add them if we are doing an out-of-tree build,
220 unless we are doing the dance to update the `Cargo.lock` (see
221 above) since in that case all the relevant files can be found
222 by cargo in the build directory.
224 The arguments added are
226 --manifest-path=<path/to/Cargo.toml>
230 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
232 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
233 makes any difference with `-m`, since otherwise no
234 `--target-dir` would be passed anyway. Additionally this is
235 done automatically when nailing-cargo sees that the cargo
236 subcommand is one which needs it, eg `fetch'.
238 * `-o` | `--online` | `--offline` | `-O`
240 Whether to allow cargo to make network access. nailing-cargo
241 always passes `--offline` to cargo, unless `--online` is in
242 force. The default is offline, unless the cargo subcommand is
243 one which implies online (currently, `fetch').
248 nailing-cargo reads these configuration files:
250 /etc/nailing-cargo/cfg.toml
251 ~/.nailing-cargo.toml
252 ./.nailing-cargo.toml
253 ../Nailing-Cargo.toml
256 Settings in later-mentioned files override ones in earlier-mentioned
259 Note that unlike everything else, `packages` and `subdirs` are read
260 only from `Cargo.nail` (see "Limitations and bugs", below).
262 Alternative `Cargo.lock` filename
263 ---------------------------------
265 To control use of alternative `Cargo.lock` filename, use the section
266 `[alt_cargolock]`. Settings here:
268 * `file = false`: disables this feature
270 * `file = true`: equivalent to `file = "Cargo.lock.example"`
271 (this is the default).
273 * `file = <some leafname>`
275 * `force = false`: Use the alternative file only if it
276 already exists. (This is the default.)
278 * `force = true`: Always uses the alternative filename.
283 Normally you pass cargo as an argument to nailing-cargo. But you
284 can also pass make or any other command. You may need to pass
285 `--no-cargo-manifest-args` (aka `-M`) to nailing-cargo, to avoid
286 passing options like `--manifest-path` to make or whatever.
288 nailing-cargo passes these environment variables to the build command:
290 * `NAILINGCARGO_WORKSPHERE`: invocation `..` (parent)
291 * `NAILINGCARGO_MANIFEST_DIR`: invocation `.` (invocation directory)
292 * `NAILINGCARGO_BUILD_DIR`: build directory (even if same as source)
293 * `NAILINGCARGO_BUILDSPHERE`: only set if out of tree: parent of build dir.
295 All of these are absolute paths.
300 * nailing-cargo temporarily dirties your source trees, including
301 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
302 crashes or is interrupted these changes may be left behind.
303 Unfortunately it is not possible to avoid this temporary dirtying
304 because the cargo team have deliberately made cargo inflexible -
305 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
306 At least, running nailing-cargo again will clean up any mess
307 left by an interrupted run.
309 * Out of tree builds require a unified filesystem view: eg, different
310 users on the same host, NFS, or something. This could be improved.
312 The alternative `Cargo.lock` filename must currently be a leafname. I
313 think fixing this just involves review to check other values work
316 * The alternative `Cargo.lock` file must be on same filesystem. This is
317 not so easy to fix; we would want the existing algorithm but a
318 fallback for this case.
320 * `Cargo.nail` is unconditionally looked for in the parent directory.
321 Ideally this should be configurable, and also perhaps be able to
322 combine multiple `Cargo.nail` files? Relatedly, although
323 nailing-cargo can read multiple config files, it can only handle
324 one file specifying directories and packages.
326 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
327 rather than a more sophisticated scheme involving locking
328 particular directories. This means that if you run multiple
329 copies of nailing-cargo at once, in different directories, but
330 with `Cargo.nail` files which imply overlapping sets of package
331 directories, things will go Badly Wrong.
333 Contributing and legal
334 ======================
336 nailing-cargo is Free Software.
338 Please help improve it. Contributions (to address the limitations, or
339 to add new facilities to help work with cargo) are welcome by email to
340 `ijackson@chiark.greenend.org.uk` or via the [Salsa
341 project](https://salsa.debian.org/iwj/nailing-cargo).
343 If you plan to do substantial work, please do get in touch with a
344 sketch of your proposed changes.
349 This project accepts contributions based on the git commit
350 Signed-off-by convention, by which the contributors certify their
351 contributions according to the Developer Certificate of Origin version
352 1.1 - see the file DEVELOPER-CERTIFICATE.
354 Copyright (C) 2019-2020 Ian Jackson and others
356 This program is free software: you can redistribute it and/or modify
357 it under the terms of the GNU Affero General Public License as
358 published by the Free Software Foundation, either version 3 of the
359 License, or (at your option) any later version.
361 This program is distributed in the hope that it will be useful,
362 but WITHOUT ANY WARRANTY; without even the implied warranty of
363 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
364 GNU Affero General Public License for more details.
366 You should have received a copy of the GNU Affero General Public License
367 along with this program. If not, see <http://www.gnu.org/licenses/>.
369 Individual files generally contain the following tag in the copyright
370 notice, instead of the full licence grant text:
372 SPDX-License-Identifier: AGPL-3.0-or-later
374 As is conventional, this should be read as a licence grant.