When I run the following:

mkdir /tmp/7
cd /tmp/7

vim composer.json
(put the code from the gist in it)

mkdir src
mkdir tests

vim tests/Test.php
(put the code the test in the gist in it, but added "<?php" as first line)

vim src/app.php
(put the code form the gist in it)

php ~/composer.phar install
vendor/bin/phpunit .
(I had to add the dot?)

The output now is:
Fatal error: Class 'Monolog\TestCase' not found in /tmp/7/vendor/monolog/monolog/tests/Monolog/Formatter/FlowdockFormatterTest.php on line 18

Call Stack:
0.0003 267376 1. {main}() /tmp/7/vendor/phpunit/phpunit/phpunit:0
0.0085 729688 2. PHPUnit_TextUI_Command::main() /tmp/7/vendor/phpunit/phpunit/phpunit:36
0.0085 730672 3. PHPUnit_TextUI_Command->run() /tmp/7/vendor/phpunit/phpunit/src/TextUI/Command.php:103
0.0152 1090872 4. PHPUnit_Runner_BaseTestRunner->getTest() /tmp/7/vendor/phpunit/phpunit/src/TextUI/Command.php:125
0.3379 1609440 5. PHPUnit_Framework_TestSuite->addTestFiles() /tmp/7/vendor/phpunit/phpunit/src/Runner/BaseTestRunner.php:62
0.4158 4210864 6. PHPUnit_Framework_TestSuite->addTestFile() /tmp/7/vendor/phpunit/phpunit/src/Framework/TestSuite.php:400
0.4160 4297000 7. PHPUnit_Util_Fileloader::checkAndLoad() /tmp/7/vendor/phpunit/phpunit/src/Framework/TestSuite.php:328
0.4160 4297288 8. PHPUnit_Util_Fileloader::load() /tmp/7/vendor/phpunit/phpunit/src/Util/Fileloader.php:42
0.4164 4310440 9. include_once('/tmp/7/vendor/monolog/monolog/tests/Monolog/Formatter/FlowdockFormatterTest.php') /tmp/7/vendor/phpunit/phpunit/src/Util/Fileloader.php:58

What am I missing?

But before you explain, can you please try the xdebug_2_3 branch from github? I did fix a crash already.

Also, when I run:

vendor/bin/phpunit tests

I get:

E

Time: 80 ms, Memory: 5.75Mb

There was 1 error:

1) Test::testHealthPage
InvalidArgumentException: Identifier "monolog.logfile" is not defined.

Sorry, I forgot to add some files.

I'll try first the branch on GitHub and come back to you.

It's working with the xdebug_2_3 branch. No segmentation fault anymore.

Still want my test code?
I can create a package with everything in it, if you want.

Thanks, but no thanks. I'll make a release in the next few days.