Debugging & Packs

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Symfony has even more debugging tools. The easiest way to get all of them is to find your terminal and run:

composer require debug --dev

Find your browser, surf back to symfony.sh and search for "debug". Ah, so the debug alias will actually install a package called symfony/debug-pack. So... what's a pack?

Click to look at the package details, and then go to its GitHub repository.

Whoa! It's just a single file: composer.json! Inside, it requires six other libraries!

Sometimes, you're going to want to install several packages at once related to one feature. To make that easy, Symfony has a number of "packs", and their whole purpose is give you one easy package that actually installs several other libraries.

In this case, composer require debug will install Monolog - a logging library, phpunit-bridge - for testing, and even the profiler-pack that we already installed earlier.

If you go back to the terminal... yep! It downloaded all those libraries and configured a few recipes.

And... check this out! Refresh! Hey! Our Twig dump() got prettier! The debug-pack integrated everything together even better.

Unpacking the Pack!

Go back to your Twig template and remove that dump. Then, open composer.json. We just installed two packs: the debug-pack and the profiler-pack:

67 lines | composer.json
// ... lines 2 - 15
"require-dev": {
// ... line 17
"symfony/debug-pack": "^1.0",
// ... line 19
"symfony/profiler-pack": "^1.0"
// ... lines 22 - 65

And we now know that the debug-pack is actually a collection of about 6 libraries.

But, packs have a disadvantage... a "dark side". What if you wanted to control the version of just one of these libraries? Or what if you wanted most of these libraries, but you didn't want, for example, the phpunit-bridge. Well... right now, there's no way to do that: all we have is this one debug-pack line.

Don't worry brave space traveler! Just... unpack the pack! Yep, at your terminal, run:

composer unpack debug

The unpack command comes from Symfony flex. And... interesting! All it says is "removing symfony/debug-pack". But if you look at your composer.json:

71 lines | composer.json
// ... lines 2 - 15
"require-dev": {
"easycorp/easy-log-handler": "^1.0.2",
// ... line 18
"symfony/debug-bundle": "^3.3|^4.0",
// ... line 20
"symfony/monolog-bundle": "^3.0",
"symfony/phpunit-bridge": "^3.3|^4.0",
"symfony/profiler-pack": "^1.0",
"symfony/var-dumper": "^3.3|^4.0"
// ... lines 26 - 69

Ah! It did remove symfony/debug-pack, but it replaced it with the 6 libraries from that pack! We can now control the versions or even remove individual libraries if we don't want them.

That is the power of packs!