Composer won't use my fork

Question

I'm trying to get composer to use my own fork of a library.

Original: https://github.com/KnpLabs/php-github-api My Fork: https://github.com/TransitScreen/php-github-api

I was able to install the original with composer simply by adding this to composer.json:

{
    "require": {
        "knplabs/github-api": "~1.4"
    }
}

I followed the instructions in the documentation, and changed it to this:

{
    "repositories": [
        {
            "type": "git",
            "url": "https://github.com/TransitScreen/php-github-api.git"
        }
    ],
    "require": {
        "knplabs/github-api": "dev-master"
    },
    "minimum-stabilitiy": "dev"
}

In my forked repository I have both a master and dev-master branch created. It's not clear to me which is correct, so I made both. I've also tried by using "type" : "vcs" and removing the .git from the URL. Neither one works. I run composer update and then the composer.lock file still points to the original repo URL, not mine. So I never get my changes when I run composer install.

What am I doing wrong??

PS: I've noticed that the library I'm trying to fork has this in it's composer.json file:

"extra": {
    "branch-alias": {
        "dev-master": "1.4.x-dev"
    }
}

I haven't found any documentation to explain what effect the alias might have. For example, should my forked repository have a 1.4.x branch??

Update 1 By the way, I know some of my configurations must be correct because I when run composer update after deleting the cache, there is a moment when I see that it's reading the composer.json of my (the correct) repository. But then afterwards composer.lock still points to the original (incorrect).

Update 2 I've also tried using composer update --prefer-source but it still doesn't work.

Answer 1

I figured out the problem!

I had edited the composer.json file inside my forked repository... It looked like this:

{
    "name": "knplabs/github-api",
    "type": "library",
    "description": "GitHub API v3 client",
    "homepage": "https://github.com/TransitScreen/php-github-api",
    "keywords": ["github", "gh", "api", "gist"],
    "license": "MIT",

But I changed it to this:

{
    "name": "transitscreen/php-github-api",
    "type": "library",
    "description": "GitHub API v3 client",
    "homepage": "https://github.com/TransitScreen/php-github-api",
    "keywords": ["github", "gh", "api", "gist"],
    "license": "MIT",

I thought that the name needed to match the new repository, but I was wrong. When I changed it back to the original name, everything works!

Many thanks to @Tomas for offering useful troubleshooting tips.

I didn't see any documentation about this anywhere, so I PRed an update to the composer docs: https://github.com/composer/composer/pull/4329