Revision as of 05:41, 2 May 2014

See also the Frequently asked Tycho questions on stackoverflow.com.

Compilation

How do I embed a configurable build version?

To cause your artifacts to be branded with the a build number, modify your manifests (MANIFEST.MF, feature.xml, etc.) to specify the version as X.Y.Z.qualifier, and the corresponding pom.xml with X.Y.Z-SNAPSHOT. Tycho will replace the qualifier and SNAPSHOT with the build timestamp (in UTC).

You can set the build qualifier to a custom value by setting the forceContextQualifier property. For example:

mvn -DforceContextQualifier=M01 install

You can also set the qualifier by configuring the tycho-packaging-plugin, using some format supported by Java's SimpleDateFormat:

<plugin>
  <groupId>org.eclipse.tycho</groupId>
  <artifactId>tycho-packaging-plugin</artifactId>
  <version>${tycho-version}</version>
  <configuration>
    <format>'myprefix_'yyyyMMddHHmm</format>
  </configuration>
</plugin>

Tycho does not directly support embedding the build identifier in resources. But some workarounds have been suggested in an email thread on tycho-user.

How to configure warning/error settings of the OSGi compiler?

To configure warnings:

<plugin>
  <groupId>org.eclipse.tycho</groupId>
  <artifactId>tycho-compiler-plugin</artifactId>
  <version>${tycho-version}</version>
  <configuration>
    <compilerArgument>-warn:[+|-]warning_tokens_separated_by_comma</compilerArgument>
  </configuration>
</plugin>

The available warning tokens are listed in the Eclipse help. Same applies for the

-err

argument for configuring errors.

Alternatively, if you have per-project JDT preferences, you may advise the compiler to use these:

<plugin>
  <groupId>org.eclipse.tycho</groupId>
  <artifactId>tycho-compiler-plugin</artifactId>
  <version>${tycho-version}</version>
  <configuration>
    <compilerArguments>
      <properties>${project.basedir}/.settings/org.eclipse.jdt.core.prefs</properties>
    </compilerArguments>
  </configuration>
</plugin>

How to compile pre-processed source placed in a different directory?

In 0.13.0 you can configure your pom.xml with something like the following:

<build>
   <plugin>
      <groupId>org.eclipse.tycho</groupId>
      <artifactId>tycho-compiler-plugin</artifactId>
      <version>${tycho-version}</version>
      <configuration>
         <source>${project.basedir}/YourNewSourceDirectory</source>
         <usePdeSourceRoots>false</usePdeSourceRoots>
      </configuration>
   </plugin>
</build>

But... "usePdeSourceRoots" was removed as part of 0.14.0 (see: [1] and [2]).

In 0.16.0 it appears you you must use the build.properties.

How do I include rootfiles?

Tycho provides partial support for PDE-style rootfiles. Rootfiles are associated and installed with a feature. See the TYCHO465RootFiles test for an example of using rootfiles.

A different approach is to use the maven-assembly-plugin to assemble a zip file. We do not have a worked example, but Kai Kreuzer documented his approach that was necessary prior to the introduction of rootfile support [3].

How should I define the target platform of my tycho project?

This question is answered here: Tycho/Target Platform

What other options does the Tycho compiler support?

Run this command to get a list of options for your version of Tycho:

mvn help:describe -Dplugin=org.eclipse.tycho:tycho-compiler-plugin -Ddetail

Or you can have a look at the Maven site for Tycho.

Can I use the Tycho compiler support in non-OSGi projects, too?

When compiling regular maven projects (e.g., packaging "jar") the plugin tycho-compiler-jdt can be used to tell maven to use the JDT compiler (aka "Eclipse Compiler for Java(TM)", "ecj") for compilation. This is useful to ensure that compilation in the IDE and on the build server show the same compiler messages, specifically JDT's annotation-based null analysis can be integrated into the build in this way.

Use the following snippet in your build.pluginManagement.plugins section:

<plugin>
	<!-- Use compiler plugin with tycho as the adapter to the JDT compiler. -->
	<artifactId>maven-compiler-plugin</artifactId>
	<configuration>
		<source>1.7</source>
		<target>1.7</target>
		<compilerId>jdt</compilerId>
		<compilerArgument>-err:nullAnnot,null</compilerArgument> <!-- insert your warn/err configuration here -->
	</configuration>
	<dependencies>
		<!-- This dependency provides the implementation of compiler "jdt": -->
		<dependency>
			<groupId>org.eclipse.tycho</groupId>
			<artifactId>tycho-compiler-jdt</artifactId>
			<version>${tycho-version}</version>
		</dependency>
	</dependencies>
</plugin>

Again, a build.plugins.plugin.configuration.compilerArguments.properties element can be used to reference an existing org.eclipse.jdt.core.prefs file (see above).

Packaging

How to generate Eclipse-SourceReferences MANIFEST header?

See docs. Example for git:

<properties>
    <tycho.scmUrl>scm:git:https://git.eclipse.org/r/p/egit/egit.git</tycho.scmUrl>
</properties>
<plugin>
   <groupId>org.eclipse.tycho</groupId>
   <artifactId>tycho-packaging-plugin</artifactId>
   <version>${tycho-version}</version>
   <configuration>
      <sourceReferences>
        <generate>true</generate>
      </sourceReferences>
   </configuration>
   <dependencies>
      <dependency>
        <groupId>org.eclipse.tycho.extras</groupId>
        <artifactId>tycho-sourceref-jgit</artifactId>
        <version>${tycho-extras-version}</version>
      </dependency>
   </dependencies>
</plugin>

This will add the Eclipse-SourceReferences header including commit ID used for this build and tag (if present).

Testing

How to configure HTTP proxy settings during test execution?

Two options:

Manually configure the proxy

<build>
  <plugins>
    <plugin>
      <groupId>org.eclipse.tycho</groupId>
      <artifactId>tycho-surefire-plugin</artifactId>
      <configuration>
        <argLine>-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=1234</argLine>
      </configuration>
    </plugin>
  </plugins>
</build>

and disable the eclipse system proxy setting

    if (Platform.isRunning() && getProxyService() != null
      && getProxyService().isSystemProxiesEnabled()
      && !getProxyService().hasSystemProxies()) {
      // XXX e3.5/gtk.x86_64 activate manual proxy configuration which
      // defaults to Java system properties if system proxy support is
      // not available
     getProxyService().setSystemProxiesEnabled(false);
     getProxyService().setProxiesEnabled(true);
    }

- or -

Make sure the native org.eclipse.core.net.* fragment for your platform is included in the test runtime so eclipse will pick up proxy settings configured on OS level:

<build>
  <plugins>
    <plugin>
      <groupId>org.eclipse.tycho</groupId>
      <artifactId>tycho-surefire-plugin</artifactId>
      <configuration>
        <dependencies>
          <dependency>
            <type>p2-installable-unit</type>
            <artifactId>org.eclipse.core.net.[YOUR_PLATFORM]</artifactId>
            <version>[VERSION]</version>
          </dependency>
        </dependencies>
      </configuration>
    </plugin>
  </plugins>
</build>

How to use SWTBot or some UI tool for testing?

<build>
  <plugins>
    <plugin>
      <groupId>org.eclipse.tycho</groupId>
      <artifactId>tycho-surefire-plugin</artifactId>
      <configuration>
        <useUIHarness>true</useUIHarness>
        <useUIThread>false</useUIThread>
        <argLine>-Xms40m -Xmx512m</argLine>
      </configuration>
    </plugin>
  </plugins>
</build>

useUIHarness=true ensures the workbench is started before the tests are run. If your app requires a custom application class (viz the org.eclipse.core.runtime.applications extension point), you will likely need to configure the application.

You may wish to add --launcher.suppressErrors to the <appArgLine> element to suppress Eclipse error dialogs.

How do I add OS-specific flags?

Some OS's may require special flags (e.g., SWT on MacOS X). The easiest way is to use a Maven profile to configure a property. For example:

  <properties>
     <os-jvm-flags/> <!-- for the default case -->
  </properties>
 
  <build>
    <plugins>
      <plugin>
        <groupId>org.eclipse.tycho</groupId>
        <artifactId>tycho-surefire-plugin</artifactId>
        <version>${tycho-version}</version>
        <configuration>
          <useUIHarness>false</useUIHarness>
          <useUIThread>true</useUIThread>
          <argLine>-Xms40m -Xmx1G ${os-jvm-flags}</argLine>
        </configuration>
      </plugin>
    </plugins>
  </build>
 
  <profiles>
    <profile>
      <id>macosx-jvm-flags</id>
      <activation>
        <os><family>mac</family></os>
      </activation>
      <properties>
        <os-jvm-flags>-XstartOnFirstThread</os-jvm-flags>
      </properties>
    </profile>
  </profiles>

Alternatively you could configure the surefire plugins within a profile too.

How to add a undeclared dependency? (e.g., OSGi declarative service)

Use the tycho-surefire-plugin <dependencies> section (see the eclipse-test-plugin packaging type for an example).

How to test OSGi declarative services?

You need to add bundle org.eclipse.equinox.ds to the test runtime:

<plugin>
  <groupId>org.eclipse.tycho</groupId>
  <artifactId>tycho-surefire-plugin</artifactId>
  <configuration>
    <dependencies>
      <dependency>
        <type>p2-installable-unit</type>
        <artifactId>org.eclipse.equinox.ds</artifactId>
      </dependency>
    </dependencies>
  </configuration>
</plugin>

How do I enable assertions during testing?

Add an <argLine> to the tycho-surefire-plugin's configuration:

<build>
  <pluginManagement>
    <plugins>
      <plugin>
        <groupId>org.eclipse.tycho</groupId>
        <artifactId>tycho-surefire-plugin</artifactId>
        <version>${tycho-version}</version>
        <configuration>
          <argLine>-ea</argLine>
        </configuration>
      </plugin>
    </plugins>
  </pluginManagement>
</build>

How can I debug my tests?

Add -DdebugPort=8000 to your Maven commandline and attach a remote debug session.

See the docs http://www.eclipse.org/tycho/sitedocs/tycho-surefire/tycho-surefire-plugin/test-mojo.html#debugPort

Diagnosing Build Problems

What does Tycho's message "XXXX" mean?

See the Tycho Messages Explained page.

My build fails with a ClassCastException of a Tycho class. What is wrong?

ClassCastExceptions indicate that different Tycho versions are used in the same reactor. This is not supported. The problem typically occurs if some of the modules use the incorrect parent POM, e.g. an older version of the correct parent. Check the parent configuration in all modules of the reactor.

How to switch on eclipse tracing during test execution?

Eclipse has a platform tracing mechanism which is switched on by using commandline option -debug and configured by putting a file named .options into the installation root. You can enable this tracing mechanism for tycho test executions by running the build in debug mode using commandline option -X and putting a file .options into the test project root.

E.g. a file .options with content

org.eclipse.osgi/resolver/debug=true
org.eclipse.osgi/resolver/wiring=true

will switch on equinox wiring tracing. You may find it useful to use the "tee" command, since running the build in debug mode may generate a lot of output. An example of this syntax is:

cd tests/myPlugin
mvn clean install -debug -X  | tee testout.txt

Why is my app not working?

Many people post to tycho-user when they are encounter problems attempting to run their deployed applications, where the apps are missing icons, or throwing ClassNotFoundException and NoClassDefFoundError exceptions. Most of these problems are traced to errors in the projects' OSGi/p2 metadata. Some common issues are:

• a bundle declares a runtime dependencies as optional, but the dependency is actually not optional;
• the build.properties does not include some key directories or resources;
• the class files are not being bundled into a library, but the classpath does not include ".".

Tycho is not the cause of these issues, but Tycho does help "discover" these issues.

Sources of help:

• The PDE FAQ, particularly the section on Build and Deployment Errors.
• Tips on diagnosing bundle load failures.

How do I disable P2 mirrors?

Often times eclipse.org redirects P2 repository requests to a misconfigured/broken/unavailable P2 mirror repository and builds fail because of that. To disable use of P2 mirrors and force all downloads to go directly to the main repository specify the following maven command line parameter

-Dtycho.disableP2Mirrors=true

It is also possible to set this property in a user/global settings.xml file. Here is settings.xml snippet:

 <profiles>
   ...
   <profile>
     <id>p2</id>
     <properties>
       <tycho.disableP2Mirrors>true</tycho.disableP2Mirrors>
     </properties>
   </profile>
 </profiles>
 
 <activeProfiles>
   ...
   <activeProfile>p2</activeProfile>
 </activeProfiles>

Whether to use proxy or not is environment-specific configuration and as such does not belong in a pom.xml in the source tree.

Why do some images not get updated in the native launcher for Windows?

Short answer: The tycho-p2-publisher-plugin does not read the location of one of the images from the .product file. This is reported as bug 433971 . As a workaround, use an ICO file with 7 uncompressed bitmaps. Also see related stackoverflow answer by Andrew Niefer

Explanation: For Windows, the process of replacing the images in the native launcher is described below. The processing is done by p2 class: org.eclipse.pde.internal.swt.tools.IconExe

This class looks at the resources of native launcher and notes the bitmaps that are in there: their sizes and their color depth. Then it looks at the provided images. This can be a list of separate BPMs or an ICO file containing multiple BMPs. Their sizes and color depths are also noted. This only works when all provided images are uncompressed. When one or more of the images is compressed, the process stops and no bitmaps are replaced in the native launcher. Next it tries to match the provided BMP sizes and color depths to the ones in the native launcher and where they match, they are replaced in the native launcher. When one or more bitmaps in the native launcher are not available in the provided images, the following message is written to System.err:

Error - <n> icon(s) not replaced in […]using […]

The class IconExe has a main method and can be run as stand-alone. Its first argument is the native launcher that needs to be modified and the following arguments are the provided BPM or ICO files.

For Eclipse 4.3(.x), the native launcher contains 7 bitmaps:

• 256x256, 32 bit (RGB / Alpha Channel)
• 48x48, 32 bit (RGB / Alpha Channel)
• 32x32, 32 bit (RGB / Alpha Channel)
• 16x16, 32 bit (RGB / Alpha Channel)
• 48x48, 8 bit (256 colors)
• 32x32, 8 bit (256 colors)
• 16x16, 8 bit (256 colors)

So, for the process of replacing the images to be successful, 7 images with the same size and depth need to be provided, either as separate BMPs or inside an ICO.

However, when using the tycho-p2-publisher-plugin, you cannot provide 7 separate BPMs, since the tycho-p2-publisher-plugin is not aware of the 256x256x32 image when it is specified in the .product file. Its class org.eclipse.tycho.model.Launcher only reads the other 6 image locations from the .product file and hence, the 7th image (the 256x256x32 one) is skipped. Therefore, the list that IconExe gets is one image short and will always report:

Error - 1 icon(s) not replaced in […]using […]

The solution that worked for us was to combine the 7 BMPs into one ICO file and provide that in the .product file.

But note that some image manipulation applications, that can create ICO files, tend to compress the 256x256x32 image by default. This is what got us on the wrong foot. So be careful that all images in the ICO file are uncompressed.

Documentation

Where can I find the Maven generated documentation for the Tycho plug-ins?

The documentation is available at:

http://www.eclipse.org/tycho/sitedocs/

and

http://www.eclipse.org/tycho/sitedocs-extras/

For more info see Tycho/Reference_Plugin_Docs.