Error after composer update - symfony

Question

I recently made a composer update on my Symfony app (2.7). Since I did this update, swiftmailer went from 2.4 to 2.5 and after the command, the console displayed me this error:
[RuntimeException]
An error occurred when executing the "'cache:clear --no-warmup'" command:
[Symfony\Component\DependencyInjection\Exception\InvalidArgumentException]
Unable to replace alias "swiftmailer.mailer.default.transport.real" with actual definition "mail".
[Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException]
You have requested a non-existent service "mail".
I tried to remove the swiftmailer directory in "vendor", but it didnt work.
Here's my composer.json:
{
"name": "symfony/framework-standard-edition",
"license": "MIT",
"type": "project",
"description": "The \"Symfony Standard Edition\" distribution",
"autoload": {
"psr-4": { "": "src/" }
},
"require": {
"php": ">=5.3.9",
"symfony/symfony": "2.7.*",
"doctrine/orm": "^2.4.8",
"doctrine/doctrine-bundle": "~1.4",
"symfony/assetic-bundle": "~2.3",
"symfony/swiftmailer-bundle": "~2.3",
"symfony/monolog-bundle": "~2.4",
"sensio/distribution-bundle": "~4.0",
"sensio/framework-extra-bundle": "^3.0.2",
"incenteev/composer-parameter-handler": "~2.0",
"friendsofsymfony/user-bundle": "dev-master"
},
"require-dev": {
"sensio/generator-bundle": "~2.3",
"symfony/phpunit-bridge": "~2.7"
},
"scripts": {
"symfony-scripts": [
"Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget"
],
"post-install-cmd": [
"#symfony-scripts"
],
"post-update-cmd": [
"#symfony-scripts"
]
},
"config": {
"bin-dir": "bin",
"platform": {
"php": "7.0"
}
},
"extra": {
"symfony-app-dir": "app",
"symfony-web-dir": "web",
"symfony-assets-install": "relative",
"incenteev-parameters": {
"file": "app/config/parameters.yml"
},
"branch-alias": {
"dev-master": "2.7-dev"
}
}
}
Thank you in advance for your help.

Answer 1

This has definitely been happening since today. (I'm on Symfony 2.8.17.) Reverting the Swiftmailer bundle back to version 2.4 fixed this for me.
In your composer.json file change
"symfony/swiftmailer-bundle": "~2.3",
to
"symfony/swiftmailer-bundle": "2.4",
Now do a composer update so you go back to version 2.4 of the Swiftmailer bundle and all should be well. Looks like there is a bug in the 2.5 update.
--
If you're still having problems try these commands to fully flush out cache:
rm -rf app/cache/*
rm app/bootstrap.php.cache
Also check your composer.lock file to ensure that the Swiftmailer bundle really has reverted back to 2.4. You should see a section like this:
{
"name": "symfony/swiftmailer-bundle",
"version": "v2.4.2",
"source": {
"type": "git",
"url": "https://github.com/symfony/swiftmailer-bundle.git",
"reference": "ad751095576ce0c12a284e30e3fff80c91f27225"
},
"dist": {
"type": "zip",
"url": "https://api.github.com/repos/symfony/swiftmailer-bundle/zipball/ad751095576ce0c12a284e30e3fff80c91f27225",
"reference": "ad751095576ce0c12a284e30e3fff80c91f27225",
"shasum": ""
},
"require": {
"php": ">=5.3.2",
"swiftmailer/swiftmailer": ">=4.2.0,~5.0",
"symfony/config": "~2.7|~3.0",
"symfony/dependency-injection": "~2.7|~3.0",
"symfony/http-kernel": "~2.7|~3.0"
},
"require-dev": {
"symfony/console": "~2.7|~3.0",
"symfony/framework-bundle": "~2.7|~3.0",
"symfony/phpunit-bridge": "~2.7|~3.0",
"symfony/yaml": "~2.7|~3.0"
},
"suggest": {
"psr/log": "Allows logging"
},
"type": "symfony-bundle",
"extra": {
"branch-alias": {
"dev-master": "2.4-dev"
}
},
"autoload": {
"psr-4": {
"Symfony\\Bundle\\SwiftmailerBundle\\": ""
}
},
"notification-url": "https://packagist.org/downloads/",
"license": [
"MIT"
],
"authors": [
{
"name": "Symfony Community",
"homepage": "http://symfony.com/contributors"
},
{
"name": "Fabien Potencier",
"email": "fabien#symfony.com"
}
],
"description": "Symfony SwiftmailerBundle",
"homepage": "http://symfony.com",
"time": "2016-12-20T04:44:33+00:00"
},

Answer 2

Most likely the issue you're describing was not caused by a bug, but by changed related dependency to swiftmailer/swiftmailer.
You have requested a non-existent service "mail". says that a service mail is missing, Unable to replace alias "swiftmailer.mailer.default.transport.real" with actual definition "mail". is a broad hint that this is related to swfitmailer transport mail, the class Swift_Transport_MailTransport using insecure php mail() function. This transport is deprecated since
swiftmailer version 5.4.5 for security reasons.
In order to fix the issue, you need to
switch from transport mail to a transport supported by current swiftmailer, or
add "swiftmailer/swiftmailer": "<6.0" to your composer.json dependencies in order to prevent packages from installing swiftmailer v6.x where Swift_Transport_MailTransport is gone. Unfortunately, symfony/swiftmailer-bundle requires swiftmailer v6.x starting from v3.0.0, so you would need to require "symfony/swiftmailer-bundle": "^2"