- Root composer.json requires foo/a 2.*, it is satisfiable by foo/a[2.0.0] from package repo (defining 1 package) but foo/a[1.0.0] from package repo (defining 1 package) has higher repository priority. The packages with higher priority do not match your constraint and are therefore not installable. See https://getcomposer.org/repoprio for details and assistance.