System Properties

Tycho understands some system properties beyond the ones documented in the respective goals to fine-tune certain behavior and to help with troubleshooting.

Disclaimer: This page is incomplete.

Common Properties

These properties are understood by the Tycho-core and affect all maven plugins:

Name Value Documentation
tycho.mode maven Completely disables the Tycho lifecycle participant in Maven. For standard Tycho use-cases this is typically not necessary, since e.g. the clean goal already disables this. However, this can be useful when explicitly invoking external goals, e.g. mvn -Dtycho.mode=maven com.foo.bar:some-plugin:some-goal, in order to improve performance.

Troubleshooting

Name Value Documentation
tycho.debug.artifactcomparator any In tycho-p2-plugin, output verbose artifact comparison information during baseline validation
tycho.debug.resolver true or artifactId Enable debug output for the artifact resolver for all projects or the project with the given artifactId

Baseline compare

Name Value Default Documentation
tycho.comparator.showDiff true / false false If set to true if text-like files show a unified diff of possible differences in files
tycho.comparator.threshold bytes 5242880 (~5MB) gives the number of bytes for content to be compared semantically, larger files will only be compared byte-by-byte

P2

These properties control the behaviour of P2 used by Tycho

Name Value Default Documentation
eclipse.p2.mirrors true / false true Each p2 site can define a list of artifact repository mirrors, this controls if P2 mirrors should be used. This is independent from configuring mirrors in the maven configuration to be used by Tycho!
eclipse.p2.maxDownloadAttempts any positive integer 3 Describes how often Tycho attempts to re-download an artifact from a p2 repository in case e.g. a bad mirror was used. One can think of this value as the maximum number of mirrors Tycho/p2 will check.