spago
(IPA: /ΛspaΙ‘o/)
PureScript package manager and build tool powered by Dhall and package-sets.
Installation
The recommended installation method for Windows, Linux and macOS is npm
(see the latest releases on npm
here):
npm install -g spago
Other installation methods available:
- Download the binary from the latest GitHub release
- Compile from source by cloning this repo and running
stack install
- With Nix, using easy-purescript-nix
General notes:
- The assumption is that you already installed the PureScript compiler.
If not, get it with
npm install -g purescript
, or the recommended method for your OS. - You might have issues with
npm
and Docker (e.g. getting the message "Downloading the spago binary failed.." etc) You have two options:- either do not run npm as root, because it doesn't work well with binaries. Use it as a nonprivileged user.
- or use
--unsafe-perm
:npm install -g --unsafe-perm spago
Notes for Linux users:
- If you get networking errors (e.g. "Host Not Found") you may need to install
netbase
. For more details see this issue. - If you encounter issues with
libtinfo.so.5
, see this issue for a fix.
Notes for NixOS users: as you might expect, the npm
installation won't work because it's
dynamically linked. Use easy-purescript-nix.
Super quick tutorial
Let's set up a new project!
$ mkdir purescript-unicorns
$ cd purescript-unicorns
$ spago init
This last command will create a bunch of files:
.
βββ packages.dhall
βββ spago.dhall
βββ src
β βββ Main.purs
βββ test
βββ Main.purs
Let's take a look at the two Dhall configuration files that spago
requires:
-
packages.dhall
: this file is meant to contain the totality of the packages available to your project (that is, any package you might want to import).In practice it pulls in the official package-set as a base, and you are then able to add any package that might not be in the package set, or override existing ones.
-
spago.dhall
: this is your project configuration. It includes the above package-set, the list of your dependencies, the source paths that will be used to build, and any other project-wide setting thatspago
will use.
To build your project, run:
$ spago build
This will download the necessary dependencies and compile the sample project in the output/
directory. You can take a look at the content of output/Main/index.js
to see what kind
of JavaScript has been generated from your new Main.purs
file.
You can already see your project running, by doing
$ spago run
..which is basically equivalent to the following command:
$ node -e "require('./output/Main/index').main()"
..which imports the JS file you just looked at, and runs the main
with Node.
You can also bundle the project in a single file with an entry point, so it can be run directly (useful for CLI apps):
$ spago bundle-app
$ node .
- Design goals and reasons
- Developing and contributing
- How do I...
- Switch from
psc-package
- Switch from
bower
- See what commands and flags are supported
- Download my dependencies locally
- Build and run my project
- Test my project
- Run a repl
- List available packages
- Add a direct dependency
- Override a package in the package set with a local one
- Override a package in the package set with a remote one
- Add a package to the package set
bower link
- Verify that an addition/override doesn't break the package set
- Automagically upgrade the package set
- Monorepo
- Bundle a project into a single JS file
- Make a project with PureScript + JavaScript
- Generate documentation for my project
- Publish my library
- Use this together with
psc-package
- Get all the licenses of my dependencies
- Know which
purs
commands are run under the hood - Ignore or update the global cache
- Switch from
- Explanations
- Troubleshooting
- Internals
Design goals and reasons
Our main design goals are:
- Great UX: you're not supposed to spend your life configuring the build for your project. A good build system just does what's most expected and gets out of the way so you can focus on actually writing the software.
- Minimal dependencies: users should not be expected to install a myriad of tools on their
system to support various workflows. We depend only on
git
andpurs
being installed. - Reproducible builds: thanks to package sets and Dhall, if your project builds today it will also build tomorrow and every day after that.
Some tools that inspired spago
are: Rust's Cargo, Haskell's Stack,
psc-package
, pulp
and purp
.
Brief survey of other package managers and build tools available
pulp
is excellent, but it is only a build tool. This means that you'll have to use it with
either bower
or psc-package
:
-
If you go for
bower
, you're missing out on package-sets (that is: packages versions that are known to be working together, saving you the headache of fitting package versions together all the time). -
If you use
psc-package
, you have the problem of not having the ability of overriding packages versions when needed, leading everyone to make their own package-set, which then goes unmaintained, etc.Of course you can use the package-set-local-setup to solve this issue, but this is exactly what we're doing here: integrating all the workflow in a single tool,
spago
, instead of having to install and usepulp
,psc-package
,purp
, etc.
Developing and contributing
We'd love your help, and welcome PRs and contributions!
Some ideas for getting started:
- Build and run
spago
- Help us fix bugs and build features
- Help us improve our documentation
- Help us log bugs and open issues
For more details see the CONTRIBUTING.md
How do I...
This section contains a collection of workflows you might want to use to get things done with spago
psc-package
Switch from Do you have an existing psc-package
project and want to switch to spago
?
No problem! If you run spago init
, we'll port your existing psc-package.json
configuration into a new spago.dhall
π
Note: spago
won't otherwise touch your psc-package.json
file, so you'll have to
remove it yourself.
You'll note that most of the psc-package
commands are the same in spago
, so porting
your existing build is just a matter of search-and-replace most of the times.
bower
Switch from Switching from bower
is about the same workflow: just run spago init
and
we'll try to match the package versions in your bower.json
with the ones in
the package set, porting the packages to your spago.dhall
Note: spago
won't otherwise touch your bower.json
file, so you'll have to
remove it yourself.
Some packages might not be found or have the wrong version, in which case you'll have to carefully:
- try to run
spago install some-package
for packages in the set - add the missing packages if not in the set
See what commands and flags are supported
For an overview of the available commands, run:
$ spago --help
You will see several subcommands (e.g. build
, test
); you can ask for help
about them by invoking the command with --help
, e.g.:
$ spago build --help
This will give a detailed view of the command, and list any command-specific (vs global) flags.
Download my dependencies locally
$ spago install
This will download all the transitive dependencies of your project (i.e. the direct dependencies,
i.e. the ones listed in the dependencies
key of spago.dhall
, plus all their dependencies,
recursively) to the local .spago
folder (and the global cache, if possible).
However, running this directly is usually not necessary, as all commands that need the dependencies to be installed will run this for you.
Build and run my project
We can build the project and its dependencies by running:
$ spago build
This is just a thin layer above the PureScript compiler command purs compile
.
The build will produce very many JavaScript files in the output/
folder. These
are CommonJS modules, and you can just require()
them e.g. on Node.
It's also possible to include custom source paths when building (the ones declared in your
sources
config are always included):
$ spago build --path 'another_source/**/*.purs'
Note: the wrapper on the compiler is so thin that you can pass options to purs
.
E.g. if you wish to output your files in some other place than output/
, you can run
$ spago build --purs-args '-o myOutput/'
If you wish to automatically have your project rebuilt when making changes to source files
you can use the --watch
flag:
$ spago build --watch
# or, to clear the screen on rebuild:
$ spago build --watch --clear-screen
If you want to run the program (akin to pulp run
), just use run
:
# The main module defaults to "Main"
$ spago run
# Or define your own module path to Main
$ spago run --main ModulePath.To.Main
# And pass arguments through to `purs compile`
$ spago run --main ModulePath.To.Main --purs-args '--verbose-errors'
# Or pass arguments to node
$ spago run --node-args "arg1 arg2"
Test my project
You can also test your project with spago
:
# Test.Main is the default here, but you can override it as usual
$ spago test --main Test.Main
Build succeeded.
You should add some tests.
Tests succeeded.
Run a repl
As with the build
and test
commands, you can add custom source paths
to load, and pass options to the underlying purs repl
by just putting
them after --
.
E.g. the following opens a repl on localhost:3200
:
$ spago repl -- --port 3200
List available packages
It is sometimes useful to know which packages are contained in our package set (e.g. to see which version we're using, or to search for packages).
You can get a complete list of the packages your packages.dhall
imports (together
with their versions and URLs) by running:
$ spago list-packages
By passing the --filter
flag you can restrict the list to direct or transitive dependencies:
# Direct dependencies, i.e. only the ones listed in spago.dhall
$ spago list-packages --filter=direct
# Transitive dependencies, i.e. all the dependencies of your dependencies
$ spago list-packages -f transitive
Add a direct dependency
You can add dependencies that are available in your package set by running:
# E.g. installing Halogen
$ spago install halogen
# This also supports multiple packages
$ spago install foreign simple-json
Override a package in the package set with a local one
Let's say I'm a user of the simple-json
package. Now, let's say I stumble upon a bug
in there, but thankfully I figure how to fix it. So I clone it locally and add my fix.
Now if I want to test this version in my current project, how can I tell spago
to do it?
We have a overrides
record in packages.dhall
just for that!
In this case we override the package with its local copy, which must have a spago.dhall
.
(it should be enough to do spago init
to have the Bower configuration imported)
It might look like this:
let overrides =
{ simple-json = ../purescript-simple-json/spago.dhall as Location
}
Note that if we list-packages
, we'll see that it is now included as a local package:
$ spago list-packages
...
signal v10.1.0 Remote "https://github.com/bodil/purescript-signal.git"
sijidou v0.1.0 Remote "https://github.com/justinwoo/purescript-sijidou.git"
simple-json local Local "./../purescript-simple-json"
simple-json-generics v0.1.0 Remote "https://github.com/justinwoo/purescript-simple-json-generics.git"
smolder v11.0.1 Remote "https://github.com/bodil/purescript-smolder.git"
...
And since local packages are just included in the build, if we add it to the dependencies
in spago.dhall
and then do spago install
, it will not be downloaded.
Override a package in the package set with a remote one
Let's now say that we test that our fix works, and we are ready to Pull Request the fix.
So we push our fork and open the PR, but while we wait for the fix to land on the next package-set release, we still want to use the fix in our production build.
In this case, we can just change the override to point to some commit of our fork, like this:
let overrides =
{ simple-json =
upstream.simple-json
// { repo = "https://github.com/my-user/purescript-simple-json.git"
, version = "701f3e44aafb1a6459281714858fadf2c4c2a977"
}
}
Note: you can use a "branch", a "tag" or a "commit hash" as a version
.
Generally it's recommended that you avoid using branches, because if you push new
commits to a branch, spago
won't pick them up unless you delete the .spago
folder.
Add a package to the package set
If a package is not in the upstream package-set, you can add it in a similar way,
by changing the additions
record in the packages.dhall
file.
E.g. if we want to add the facebook
package:
let additions =
{ facebook =
{ dependencies =
[ "console"
, "aff"
, "prelude"
, "foreign"
, "foreign-generic"
, "errors"
, "effect"
]
, repo =
"https://github.com/Unisay/purescript-facebook.git"
, version =
"v0.3.0"
}
}
As you might expect, this works also in the case of adding local packages:
Example:
let additions =
{ foobar = ../foobar/spago.dhall as Location
}
bower link
See how to add local packages or override existing ones
Verify that an addition/override doesn't break the package set
"But wait", you might say, "how do I know that my override doesn't break the package set?"
This is a fair question, and you can verify that your fix didn't break the rest of the
package-set by running the verify
command.
E.g. if you patched the foreign
package, and added it as a local package to your package-set,
you can check that you didn't break its dependents (also called "reverse dependencies")
by running:
$ spago verify foreign
Once you check that the packages you added verify correctly, we would of course very much love if you could pull request it to the Upstream package-set β€οΈ
If you decide so, you can read up on how to do it here.
Automagically upgrade the package set
The version of the package-set you depend on is fixed in the packages.dhall
file
(look for the upstream
var).
You can upgrade to the latest version of the package-set with the upgrade-set
command, that will automatically find out the latest version, download it, and write
the new url and hashes in the packages.dhall
file for you.
Running it would look something like this:
$ spago upgrade-set
Found the most recent tag for "purescript/package-sets": "psc-0.12.3-20190227"
Package-set upgraded to latest tag "psc-0.12.3-20190227"
Fetching the new one and generating hashes.. (this might take some time)
Done. Updating the local package-set file..
If you wish to detach from tags for your package-set, you can of course point it to a
specific commit. Just set your upstream
to look something like this:
let upstream =
https://github.com/purescript/package-sets/blob/81354f2ea1ac9493eb05dfbd43adc6d183bc4ecd/src/packages.dhall
Monorepo
Spago aims to support "monorepos", allowing you to split a blob of code into different "compilation units" that might have different dependencies, deliverables, etc.
A typical monorepo setup in spago consists of:
- some "libraries" (i.e. packages that other packages will depend on), each having their own
spago.dhall
- some "apps" (i.e. packages that no one depends on), each having their own
spago.dhall
- a single
packages.dhall
, that includes all the "libraries" as local packages, and that allspago.dhall
files refer to - this is so that all packages share the same package set.
So for example if you have lib1
, lib2
and app1
, you might have the following file tree:
.
βββ app1
β βββ spago.dhall
β βββ src
β β βββ Main.purs
β βββ test
β βββ Main.purs
βββ lib1
β βββ spago.dhall
β βββ src
β βββ Main.purs
βββ lib2
β βββ spago.dhall
β βββ src
β βββ Main.purs
βββ packages.dhall
Then:
- the top level
packages.dhall
might look like this:
let upstream = https://raw.githubusercontent.com/purescript/package-sets/psc-0.13.0-20190626/src/packages.dhall sha256:9905f07c9c3bd62fb3205e2108515811a89d55cff24f4341652f61ddacfcf148
let overrides =
{ lib1 = ./lib1/spago.dhall as Location
, lib2 = ./lib2/spago.dhall as Location
}
in upstream // overrides
lib1/spago.dhall
might look something like this:
{ name =
"lib1"
, dependencies =
[ "effect"
, "console"
, "prelude"
]
, sources =
[ "src/**/*.purs" ]
, packages =
../packages.dhall -- Note: this refers to the top-level packages file
}
- assuming
lib1
depends onlib2
,lib2/spago.dhall
might look something like this:
{ name =
"lib2"
, dependencies =
[ "effect"
, "console"
, "prelude"
, "lib1" -- Note the dependency here
]
, sources =
[ "src/**/*.purs" ]
, packages =
../packages.dhall
}
- and then
app1/spago.dhall
might look something like this:
{ name =
"app1"
, dependencies =
-- Note: the app does not include all the dependencies that the lib included
[ "prelude"
, "simple-json" -- Note: this dep was not used by the library, only the app uses it
, "lib2" -- Note: we add `lib2` as dependency
]
, packages =
-- We also refer to the top-level packages file here, so deps stay in sync for all packages
../packages.dhall
}
Note that you can also handle as a "monorepo" a simpler situation where you want to "split" dependencies, so e.g. if you want to not include your test dependencies in your app's dependencies, you can have a "test" project depend on the "app" project.
Bundle a project into a single JS file
For the cases when you wish to produce a single JS file from your PureScript project, there are basically two ways to do that:
spago bundle-app
1. This will produce a single, executable, dead-code-eliminated file:
# You can specify the main module and the target file, or these defaults will be used
$ spago bundle-app --main Main --to index.js
Bundle succeeded and output file to index.js
# We can then run it with node:
$ node .
spago bundle-module
2. If you wish to produce a single, dead-code-eliminated JS module that you can require
from
JavaScript:
# You can specify the main module and the target file, or these defaults will be used
$ spago bundle-module --main Main --to index.js
Bundling first...
Bundle succeeded and output file to index.js
Make module succeeded and output file to index.js
$ node -e "console.log(require('./index).main)"
[Function]
Skipping the Build Step
When running spago bundle-app
and spago bundle-module
the build
step will also execute
since bundling depends on building first.
To skip this build you can add the --no-build
flag.
Make a project with PureScript + JavaScript
Take a look at TodoMVC with react-basic + spago + parcel to have a starting point.
This generally consists of two separate build steps:
- Build the project with
spago
:
- this will compile your project to JS
- you can use either
spago build
- which will create many files that you can require in your JS - orspago bundle-module
, which will create only one Dead-Code-Eliminated file that you can require. - the tradeoff between the two is compile times vs bundle size:
bundle-module
will be more expensive to build, but will generally be smaller, while just requiring the artifacts frombuild
is very fast to compile but might lead to a bigger bundle (you should benchmark this though)
- Bundle the project with a JS bundler:
- this will usually bundle everything in a single JS file, after resolving all the
require
s and including the JS dependencies - you'll usually have a
index.js
file in your project, that will include something like:.. // So you require the PureScript file from js var PureScriptMain = require('./output/Main'); .. // Then you can just call its functions from js PureScriptMain.somemethod();
- the above example project uses
parcel
, but you can usewebpack
,browserify
, etc.
Generate documentation for my project
To build documentation for your project and its dependencies (i.e. a "project-local
Pursuit"), you can use the docs
command:
$ spago docs
This will generate all the documentation in the ./generated-docs
folder of your project.
You might then want to open the index.html
file in there.
To build the documentation as Markdown instead of HTML, or to generate tags for your project,
you can pass a format
flag:
$ spago docs --format ctags
Publish my library
If you wish to develop a library with spago
you can definitely do so, and use it to
manage and build your project, until you need to "publish" your library, where you'll need
to use pulp
.
When you decide you want to publish your library for others to use, you should:
- run
spago bump-version --no-dry-run <BUMP>
. This will generate abower.json
in a new commit in Git that is tagged with the version. - run
pulp publish
. This will ensure the package is registered in Bower, push the version tag to Git and upload documentation to Pursuit.
This is because the PureScript ecosystem uses the Bower registry as a "unique names registry".
So in order to "publish" a package one needs to add it there, and eventually to package-sets
.
Consequentially, package-sets requires (full instructions here)
that packages in it:
- are in the Bower registry
- use
spago bump-version
orpulp version
(because this gives versions withvX.Y.Z
) - use
pulp publish
(so that's it's available on the Bower registry and on Pursuit)
All of this will be automated in future versions, removing the need for Pulp.
A library published in this way is purescript-rave.
psc-package
Use this together with spago
can help you setup your psc-package
project to use the Dhall version of the package set.
We have two commands for it:
-
psc-package-local-setup
: this command creates apackages.dhall
file in your project, that points to the most recent package set, and lets you override and add arbitrary packages. See the docs about this here. -
psc-package-insdhall
: do the Ins-Dhall-ation of the local project setup: that is, generates a local package set forpsc-package
from yourpackages.dhall
, and points yourpsc-package.json
to it.Functionally this is equivalent to running:
NAME='local' TARGET=.psc-package/$NAME/.set/packages.json mkdir -p .psc-package/$NAME/.set dhall-to-json --pretty <<< './packages.dhall' > $TARGET echo wrote packages.json to $TARGET
Get all the licenses of my dependencies
For compliance reasons, you might need to fetch all the LICENSE
files of your dependencies.
To do this you can exploit the list-packages
command with its --filter
flag.
E.g. if you want to print out all the LICENSE
files of your direct dependencies:
#!/usr/bin/env bash
# Note: the `awk` part is to cut out only the package name
for dep in $(spago list-packages -f direct | awk '{print $1}')
do
cat $(find ".spago/${dep}" -iname 'LICENSE')
done
purs
commands are run under the hood
Know which The -v
flag will print out all the purs
commands that spago
invokes during its operations,
plus a lot of diagnostic info, so you might want to use it to troubleshoot weird behaviours
and/or crashes.
Ignore or update the global cache
There is a global cache that spago
uses to avoid re-downloading things - its
location will be printed if you call e.g. spago install -v
.
It's possible to change the behaviour of the global cache with the --global-cache
flag
that is accepted by many commands. You can either:
- skip the cache with
--global-cache=skip
: in this case the global cache will be ignored and the local project will re-download everything - update the cache to the latest version with
--global-cache=update
: this might be useful if you want to globally cache a tag or commit that is newer than 24h - the timespago
will wait before updating its metadata file about "which things are globally cacheable".
Explanations
Visual Overview: What happens when you do 'spago build'?
Configuration file format
It's indeed useful to know what's the format (or more precisely, the Dhall
type) of the files that spago
expects. Let's define them in Dhall:
-- The basic building block is a Package:
let Package =
{ dependencies : List Text -- the list of dependencies of the Package
, repo = Text -- the address of the git repo the Package is at
, version = Text -- git tag
}
-- The type of `packages.dhall` is a Record from a PackageName to a Package
-- We're kind of stretching Dhall syntax here when defining this, but let's
-- say that its type is something like this:
let PackageSet =
{ console : Package
, effect : Package
... -- and so on, for all the packages in the package-set
}
-- The type of the `spago.dhall` configuration is then the following:
let Config =
{ name : Text -- the name of our project
, dependencies : List Text -- the list of dependencies of our app
, sources : List Text -- the list of globs for the paths to always include in the build
, packages : PackageSet -- this is the type we just defined above
}
spago
also install my npm dependencies?
Why can't A common scenario is that you'd like to use things like react-basic
, or want to depend
on JS libraries like ThreeJS.
In any case, you end up depending on some NPM package.
And it would be really nice if spago
would take care of installing all of these
dependencies, so we don't have to worry about running npm besides it, right?
While these scenarios are common, they are also really hard to support.
In fact, it might be that a certain NPM package in your transitive dependencies
would only support the browser, or only node. Should spago
warn about that?
And if yes, where should we get all of this info?
Another big problem is that the JS backend is not the only backend around. For example, PureScript has a C backend and an Erlang backend among the others.
These backends are going to use different package managers for their native dependencies,
and while it's feasible for spago
to support the backends themselves, supporting also
all the possible native package managers (and doing things like building package-sets for their
dependencies versions) is not a scalable approach (though we might do this in the future if
there's enough demand).
So this is the reason why if you or one of your dependencies need to depend on some "native" packages, you should run the appropriate package-manager for that (e.g. npm).
For examples on how to do it, see next section.
Why we don't resolve JS dependencies when bundling, and how to do it
spago
only takes care of PureScript land. In particular, bundle-module
will do the
most we can do on the PureScript side of things (dead code elimination), but will
leave the require
s still in.
To fill them in you should use the proper js tool of the day, at the time of writing ParcelJS looks like a good option.
If you wish to see an example of a project building with spago
+ parcel
, a simple
starting point is the TodoMVC app with react-basic
.
You can see in its package.json
that a "production build" is just
spago build && parcel build index.html
.
If you open its index.js
you'll see that it does a require('./output/Todo.App')
:
the files in output
are generated by spago build
, and then the parcel
build resolves
all the require
s and bundles all these js files in.
Though this is not the only way to include the built js - for a slimmer build or for importing
some PureScript component in another js build we might want to use the output of bundle-module
.
For an example of this in a "production setting" you can take a look at affresco. It is a PureScript monorepo of React-based components and apps.
The gist of it is that the PureScript apps in the repo are built with spago build
(look in the package.json
for it), but all the React components can be imported from
JS apps as well, given that proper modules are built out of the PS sources.
This is where spago bundle-module
is used: the build-purs.rb
builds a bundle out of every
single React component in each component's folder - e.g. let's say we bundle-module
from
the ksf-login
component and output it in the index.js
of the component's folder; we can
then yarn install
the single component (note it contains a package.json
), and require it
as a separate npm package with require('@affresco/ksf-login')
.
How does the "global cache" work?
Every time spago
will need to "install dependencies" it will:
-
check if the package is local to the filesystem: if it is then it will skip it as we can just point to the files
-
check if the ref is already in the global cache. If it is, it will just copy it to the project-local cache
-
download a metadata file from the
package-sets-metadata
repo if missing from the global cache or older 24 hours.This file contains the list of tags and commits for every package currently in the package set, updated hourly.
-
check if the tag or commit of the package we need to download is in this cached index, and if it is then this means we can "globally cache" that version - this is because commit hashes are immutable, and tags are "immutable enough"
-
if a version is deemed to be "globally cacheable" then a tarball of that ref is downloaded from GitHub and copied to both the global and the local cache
-
otherwise, the repo is just cloned to the local cache
Note: a question that might come up while reading the above might be "why not just hit GitHub to check commits and tags for every repo while installing?"
The problem is that GitHub limits token-less API requests to 50 per hour, so any decently-sized installation will fail to get all the "cacheable" items, making the global cache kind of useless. So we are just caching all of that info for everyone here.
Troubleshooting
Spago is failing with some errors about "too many open files"
This might happen because the limit of "open files per process" is too low in your OS - as
spago
will try to fetch all dependencies in parallel, and this requires lots of file operations.
You can limit the number of concurrent operations with the -j
flag, e.g.:
$ spago -j 10 install
To get a ballpark value for the j
flag you can take the result of the ulimit -n
command
(which gives you the current limit), and divide it by four.
Package set caching problems
If you encounter any issues with the hashes for the package-set (e.g. the hash is not deemed
correct by spago
), then you can have the hashes recomputed by running the freeze
command:
$ spago freeze
However, this is a pretty rare situation and in principle it should not happen, and when it happens it might not be secure to run the above command.
To understand all the implications of this I'd invite you to read about the safety guarantees that Dhall offers.
packages.dhall
, but spago
is not installing it. Why?
I added a new package to the Adding a package to the package-set just includes it in the set of possible packages you
can depend on. However, if you wish spago
to install it you should then add it to
the dependencies
list in your spago.dhall
.
Internals
See this document