composer: Self version parsing broken on latests Travis trusty stable build with Git 2.x update

My package: https://github.com/ezsystems/ezpublish-kernel Example job: https://travis-ci.org/ezsystems/ezpublish-kernel/jobs/181321568

Script triggering the defect (On travis trusty):

# Important: I don't know how Travis clones repo, but depth is set to 30, and always have been.
# On the shallow checkout, the following is executed on the given job:

phpenv config-rm xdebug.ini
composer require --no-update ezsystems/ezplatform-solr-search-engine:^1.1.0@dev
composer update --no-progress --no-interaction --prefer-dist

Output of composer update:

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
    - ezsystems/ezplatform-solr-search-engine v1.1.0 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.0-beta1 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.0-rc1 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.0-rc2 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.1 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.1-rc1 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.2-beta1 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.2-rc1 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.2-rc2 requires ezsystems/ezpublish-kernel ^6.5@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.0, v6.5.1, v6.5.1.1, v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine 1.1.x-dev requires ezsystems/ezpublish-kernel ^6.5.2@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.2.1 requires ezsystems/ezpublish-kernel ^6.5.2@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.1.3 requires ezsystems/ezpublish-kernel ^6.5.2@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.2, v6.6.0, v6.6.1].
    - ezsystems/ezplatform-solr-search-engine v1.2.0-alpha1 requires ezsystems/ezpublish-kernel ^6.5.2@dev -> satisfiable by ezsystems/ezpublish-kernel[v6.5.2, v6.6.0, v6.6.1].
    - don't install ezsystems/ezpublish-kernel v6.5.0|remove ezsystems/ezpublish-kernel No version set (parsed as 1.0.0)
    - don't install ezsystems/ezpublish-kernel v6.5.1|remove ezsystems/ezpublish-kernel No version set (parsed as 1.0.0)
    - don't install ezsystems/ezpublish-kernel v6.5.1.1|remove ezsystems/ezpublish-kernel No version set (parsed as 1.0.0)
    - don't install ezsystems/ezpublish-kernel v6.5.2|remove ezsystems/ezpublish-kernel No version set (parsed as 1.0.0)
    - don't install ezsystems/ezpublish-kernel v6.6.0|remove ezsystems/ezpublish-kernel No version set (parsed as 1.0.0)
    - don't install ezsystems/ezpublish-kernel v6.6.1|remove ezsystems/ezpublish-kernel No version set (parsed as 1.0.0)
    - ezsystems/ezplatform-solr-search-engine v1.2.0-beta1 requires ezsystems/ezpublish-kernel ^6.7.0@dev -> satisfiable by ezsystems/ezpublish-kernel[6.7.x-dev, v6.7.0-beta1] but these conflict with your requirements or minimum-stability.
    - ezsystems/ezplatform-solr-search-engine 1.2.x-dev requires ezsystems/ezpublish-kernel ^6.7.0@dev -> satisfiable by ezsystems/ezpublish-kernel[6.7.x-dev, v6.7.0-beta1] but these conflict with your requirements or minimum-stability.
    - Installation request for ezsystems/ezpublish-kernel No version set (parsed as 1.0.0) -> satisfiable by ezsystems/ezpublish-kernel[No version set (parsed as 1.0.0)].
    - Installation request for ezsystems/ezplatform-solr-search-engine ^1.1.0@dev -> satisfiable by ezsystems/ezplatform-solr-search-engine[1.1.x-dev, 1.2.x-dev, v1.1.0, v1.1.0-beta1, v1.1.0-rc1, v1.1.0-rc2, v1.1.1, v1.1.1-rc1, v1.1.2-beta1, v1.1.2-rc1, v1.1.2-rc2, v1.1.2.1, v1.1.3, v1.2.0-alpha1, v1.2.0-beta1].

Important part: No version set (parsed as 1.0.0) -> satisfiable by ezsystems/ezpublish-kernel[No version set (parsed as 1.0.0)].

This happens on both stable branches (6.6) and master ("dev-master": "6.7.x-dev",).

Relevant Travis update:

• https://docs.travis-ci.com/user/build-environment-updates/2016-12-01/

Reporting here as I’m not sure if this is a issue with the git version they use and should be reported there, or composer needs to adjust for the given git version.

Current workaround for us:

# before composer update, assumes you have current branch dev version (e.g. 6.6.x-dev) set
# in composer.json extra.branch-alias, but you could have it hardcoded in ci scripts if you want
export COMPOSER_ROOT_VERSION=`php -r 'echo json_decode(file_get_contents("./composer.json"), true)["extra"]["branch-alias"]["dev-tmp_ci_branch"];'`