I did the following:
mkdir testdir
cd testdir
composer init
// answer all questions with default values, resulting in a new, clean composer.json
composer require loco/swizzle:~1.0
Result:
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
- Installing psr/log (1.0.0)
Downloading: 100%
- Installing monolog/monolog (1.7.0)
Downloading: 100%
- Installing symfony/event-dispatcher (v2.4.1)
Downloading: 100%
- Installing guzzle/guzzle (v3.8.1)
Downloading: 100%
- Installing loco/swizzle (1.0.1)
Downloading: 100%
Your problem cannot be reproduced by the information you gave. My resulting composer.json is:
{
"name": "test/test",
"authors": [
{
"name": "Test User",
"email": "test@test.example"
}
],
"require": {
"loco/swizzle": "~1.0"
}
}