Symfony 2.8 -> 3.4 Error log

# php composer.phar update symfony/symfony --with-dependencies
Dependency "symfony/polyfill-apcu" is also a root requirement, but is not explicitly whitelisted. Ignoring.
Dependency "twig/twig" is also a root requirement, but is not explicitly whitelisted. Ignoring.
Dependency "ircmaxell/password-compat" is also a root requirement, but is not explicitly whitelisted. Ignoring.
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - The requested package symfony/monolog-bundle (installed at v2.12.1, required as ^3.1.0) is satisfiable by symfony/monolog-bundle[v2.12.1] but these conflict with your requirements or minimum-stability.
  Problem 2
    - The requested package sensio/distribution-bundle (installed at v3.0.36, required as ^5.0.19) is satisfiable by sensio/distribution-bundle[v3.0.36] but these conflict with your requirements or minimum-stability.
  Problem 3
    - The requested package sensio/framework-extra-bundle (installed at v3.0.29, required as ^5.0.0) is satisfiable by sensio/framework-extra-bundle[v3.0.29] but these conflict with your requirements or minimum-stability.
  Problem 4
    - The requested package sensio/generator-bundle (installed at v2.5.3, required as ^3.0) is satisfiable by sensio/generator-bundle[v2.5.3] but these conflict with your requirements or minimum-stability.
  Problem 5
    - Conclusion: don't install symfony/symfony v3.4.8
    - Conclusion: don't install symfony/symfony v3.4.7
    - Conclusion: don't install symfony/symfony v3.4.6
    - Conclusion: don't install symfony/symfony v3.4.5
    - Conclusion: don't install symfony/symfony v3.4.4
    - Conclusion: don't install symfony/symfony v3.4.3
    - Conclusion: don't install symfony/symfony v3.4.2
    - Conclusion: don't install symfony/symfony v3.4.1
    - Conclusion: don't install symfony/symfony v3.4.0
    - Conclusion: don't install symfony/symfony v3.3.16
    - Conclusion: don't install symfony/symfony v3.3.15
    - Conclusion: don't install symfony/symfony v3.3.14
    - Conclusion: don't install symfony/symfony v3.3.13
    - Conclusion: don't install symfony/symfony v3.3.12
    - Conclusion: don't install symfony/symfony v3.3.11
    - Conclusion: don't install symfony/symfony v3.3.10
    - Conclusion: don't install symfony/symfony v3.3.9
    - Conclusion: don't install symfony/symfony v3.3.8
    - Conclusion: don't install symfony/symfony v3.3.7
    - Conclusion: don't install symfony/symfony v3.3.6
    - Conclusion: don't install symfony/symfony v3.3.5
    - Conclusion: don't install symfony/symfony v3.3.4
    - Conclusion: don't install symfony/symfony v3.3.3
    - Conclusion: don't install symfony/symfony v3.3.2
    - Conclusion: don't install symfony/symfony v3.3.1
    - Conclusion: don't install symfony/symfony v3.3.0
    - Conclusion: don't install symfony/symfony v3.2.14
    - Conclusion: don't install symfony/symfony v3.2.13
    - Conclusion: don't install symfony/symfony v3.2.12
    - Conclusion: don't install symfony/symfony v3.2.11
    - Conclusion: don't install symfony/symfony v3.2.10
    - Conclusion: don't install symfony/symfony v3.2.9
    - Conclusion: don't install symfony/symfony v3.2.8
    - Conclusion: don't install symfony/symfony v3.2.7
    - Conclusion: don't install symfony/symfony v3.2.6
    - Conclusion: don't install symfony/symfony v3.2.5
    - Conclusion: don't install symfony/symfony v3.2.4
    - Conclusion: don't install symfony/symfony v3.2.3
    - Conclusion: don't install symfony/symfony v3.2.2
    - Conclusion: don't install symfony/symfony v3.2.1
    - Conclusion: don't install symfony/symfony v3.2.0
    - Conclusion: don't install symfony/symfony v3.1.10
    - Conclusion: don't install symfony/symfony v3.1.9
    - Conclusion: don't install symfony/symfony v3.1.8
    - Conclusion: don't install symfony/symfony v3.1.7
    - Conclusion: don't install symfony/symfony v3.1.6
    - Conclusion: don't install symfony/symfony v3.1.5
    - Conclusion: don't install symfony/symfony v3.1.4
    - Conclusion: don't install symfony/symfony v3.1.3
    - Conclusion: don't install symfony/symfony v3.1.2
    - Conclusion: don't install symfony/symfony v3.1.1
    - Conclusion: don't install symfony/symfony v3.1.0
    - Conclusion: don't install symfony/symfony v3.0.9
    - Conclusion: don't install symfony/symfony v3.0.8
    - Conclusion: don't install symfony/symfony v3.0.7
    - Conclusion: don't install symfony/symfony v3.0.6
    - Conclusion: don't install symfony/symfony v3.0.5
    - Conclusion: don't install symfony/symfony v3.0.4
    - Conclusion: don't install symfony/symfony v3.0.3
    - Conclusion: don't install symfony/symfony v3.0.2
    - Installation request for guzzle/guzzle (installed at v3.9.3) -> satisfiable by guzzle/guzzle[v3.9.3].
    - Conclusion: don't install symfony/symfony v3.0.1
    - sensio/framework-extra-bundle v5.1.6 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.1.5 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.1.4 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.1.3 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.1.2 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.1.1 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.1.0 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.0.1 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - sensio/framework-extra-bundle v5.0.0 requires symfony/http-kernel ^3.3|^4.0 -> satisfiable by symfony/symfony[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8], symfony/http-kernel[v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v4.0.0, v4.0.1, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8].
    - symfony/http-kernel v3.3.0 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.1 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.10 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.11 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.12 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.13 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.14 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.15 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.16 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.2 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.3 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.4 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.5 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.6 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.7 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.8 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.3.9 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.0 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.1 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.2 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.3 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.4 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.5 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.6 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.7 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v3.4.8 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.0 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.1 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.2 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.3 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.4 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.5 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.6 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.7 conflicts with symfony/symfony[v3.0.0].
    - symfony/http-kernel v4.0.8 conflicts with symfony/symfony[v3.0.0].
    - Installation request for symfony/symfony ~3.0 -> satisfiable by symfony/symfony[v3.0.0, v3.0.1, v3.0.2, v3.0.3, v3.0.4, v3.0.5, v3.0.6, v3.0.7, v3.0.8, v3.0.9, v3.1.0, v3.1.1, v3.1.10, v3.1.2, v3.1.3, v3.1.4, v3.1.5, v3.1.6, v3.1.7, v3.1.8, v3.1.9, v3.2.0, v3.2.1, v3.2.10, v3.2.11, v3.2.12, v3.2.13, v3.2.14, v3.2.2, v3.2.3, v3.2.4, v3.2.5, v3.2.6, v3.2.7, v3.2.8, v3.2.9, v3.3.0, v3.3.1, v3.3.10, v3.3.11, v3.3.12, v3.3.13, v3.3.14, v3.3.15, v3.3.16, v3.3.2, v3.3.3, v3.3.4, v3.3.5, v3.3.6, v3.3.7, v3.3.8, v3.3.9, v3.4.0, v3.4.1, v3.4.2, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8].
    - Installation request for sensio/framework-extra-bundle ^5.0.0 -> satisfiable by sensio/framework-extra-bundle[v5.0.0, v5.0.1, v5.1.0, v5.1.1, v5.1.2, v5.1.3, v5.1.4, v5.1.5, v5.1.6].