Composer error when trying to include multi level public personal repositories - composer-php

Question

I'm splitting up some of my personal code to modularize and reuse it on different projects.
I've started using composer recently and have been using it for referencing these modules on my projects.
The following has worked for me so far:
First project composer.json
{
"name": "mpf/apimodule",
"version":"dev-main",
"autoload": {
"psr-4": {
"APIModule\\":"classes/"
}
}
}
Second project composer.json
{
"name": "mpf/crawler",
"version":"dev-main",
"autoload": {
"psr-4": {
"API\\": "classes/"
}
},
"repositories": [
{
"type": "vcs",
"url": "git#github.com:{User}/{Repo}.git"
}
],
"require": {
"fabpot/goutte": "^3.2",
"mpf/apimodule": "dev-main"
}
}
Both composers are compiled and the project works as intended.
But when I try to add a third layer
Third project composer.json
{
"autoload": {
"psr-4": {
"API\\": "classes/"
}
},
"repositories": [
{
"type": "vcs",
"url": "git#github.com:{User}/{Repo}.git"
}
],
"require": {
"mpf/crawler": "dev-main"
}
}
I get the following error when running the composer update command
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Root composer.json requires mpf/crawler dev-main -> satisfiable by mpf/crawler[dev-main].
- mpf/crawler dev-main requires mpf/apimodule dev-main -> could not be found in any
version, there may be a typo in the package name.
I've found a similar issue, but my repositories are all public and that was the problem for them.
I've tried running composer -vvv / composer diagnose, but couldn't find any useful information with the results.

Answer 1

From the description given in your question, you add repositories into root composer.json files. This works fine as long as you're using the root composer.json file. That is the project having this file.
Now while this works on each per-project basis, when you put the third (or fourth, fifth etc. ) composer.json file into the mix, or as you word it "add a third layer", it stops working.
Technically it does not stop working, however Composer can not resolve that inherited repository any longer to resolve the root dependency:
- Root composer.json requires mpf/crawler dev-main \
-> satisfiable by mpf/crawler[dev-main].
- mpf/crawler dev-main requires mpf/apimodule dev-main \
-> could not be found in any version, there may be a typo in the package name.
As honest as Composer is here, it may be puzzling in your situation. You've certainly already double-checked there is no typo and still though, Composer can not find any version.
That is because Composer uses the composer.json#/repositories configuration only from the root composer.json - that is the file itself. Let's visualize this a bit:
composer.json
vendor/mpf/crawler/composer.json
My educated guess is that, albeit you've added the repository for mpf/crawler to composer.json the repository for mpf/apimodule has not been added to it but only to vendor/mpf/crawler/composer.json.
The fix is easy, add all repositories your root project requires to resolve all dependencies to that projects configuration file (composer.json in the project you install the dependencies in).
If you think this through, it might become more clear why that is so:
The moment you install from composer.json, all repositories should be defined already as otherwise the outcome of the install will be a pure game of luck. Packages would be able to overwrite your repositories configuration and you would not be in control any longer.
My recommendations to continue your journey:
Add repositories inside your root composer.json file, to ensure your projects' configuration is complete. (Goal: understanding root configuration, the project level)
When working with this, consider if you want to have a global configuration of repositories. That is you can on the level of your computer user configure a list of repositories shared across projects (on that host). (Goal: understanding global configuration, the level of your host, working with projects)
Take a Safari-Tour on the different types of repositories Composer offers (compare with the documentation) as you may find even more in there (e.g. path repositories, another central .json file you can share etc. - there are quite some options). (Goal: understanding of the different repository configuration types)
kuba points to an entry in the Composer FAQ for this topic (via):
Why can't Composer load repositories recursively? (Composer FAQ)