Some maven plugins or processors make it fail:

[INFO] — wildfly-galleon-maven-plugin:2.0.2.Final:generate-feature-specs (feature-spec-build) @ wildfly-servlet-galleon-pack —
Downloading from thunder.maven.central.cache: https://thunder.sin2.redhat.com/maven/org/wildfly/openssl/wildfly-openssl-macosx-x86_64/$%7Bversion.org.wildfly.openssl.wildfly-openssl-macosx-x86_64%7D/wildfly-openssl-macosx-x86_64-$%7Bversion.org.wildfly.openssl.wildfly-openssl-macosx-x86_64%7D.pom
Forked embedded process has failed with the following error:
java.lang.IllegalStateException: WFLYEMB0022: Cannot invoke 'start' on embedded process
at org.wildfly.core.embedded.EmbeddedManagedProcessImpl.invokeOnServer(EmbeddedManagedProcessImpl.java:100)
at org.wildfly.core.embedded.EmbeddedManagedProcessImpl.start(EmbeddedManagedProcessImpl.java:58)
at org.wildfly.galleon.plugin.featurespec.generator.FeatureSpecGenerator.readFeatureSpecs(FeatureSpecGenerator.java:304)
at org.wildfly.galleon.plugin.featurespec.generator.FeatureSpecGenerator.forkedForEmbedded(FeatureSpecGenerator.java:232)
at org.wildfly.galleon.plugin.server.ForkedEmbeddedUtil.main(ForkedEmbeddedUtil.java:204)
org.wildfly.core.embedded.EmbeddedProcessStartException: WFLYEMB0021: Cannot start embedded process
at org.wildfly.core.embedded.EmbeddedStandaloneServerFactory$StandaloneServerImpl.start(EmbeddedStandaloneServerFactory.java:319)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.wildfly.core.embedded.EmbeddedManagedProcessImpl.invokeOnServer(EmbeddedManagedProcessImpl.java:88)
at org.wildfly.core.embedded.EmbeddedManagedProcessImpl.start(EmbeddedManagedProcessImpl.java:58)
at org.wildfly.galleon.plugin.featurespec.generator.FeatureSpecGenerator.readFeatureSpecs(FeatureSpecGenerator.java:304)
at org.wildfly.galleon.plugin.featurespec.generator.FeatureSpecGenerator.forkedForEmbedded(FeatureSpecGenerator.java:232)
at org.wildfly.galleon.plugin.server.ForkedEmbeddedUtil.main(ForkedEmbeddedUtil.java:204)
java.util.concurrent.ExecutionException: JBTHR00005: Operation failed
at org.jboss.threads.AsyncFutureTask.get(AsyncFutureTask.java:253)
at org.wildfly.core.embedded.EmbeddedStandaloneServerFactory$StandaloneServerImpl.start(EmbeddedStandaloneServerFactory.java:301)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.wildfly.core.embedded.EmbeddedManagedProcessImpl.invokeOnServer(EmbeddedManagedProcessImpl.java:88)
at org.wildfly.core.embedded.EmbeddedManagedProcessImpl.start(EmbeddedManagedProcessImpl.java:58)
at org.wildfly.galleon.plugin.featurespec.generator.FeatureSpecGenerator.readFeatureSpecs(FeatureSpecGenerator.java:304)
at org.wildfly.galleon.plugin.featurespec.generator.FeatureSpecGenerator.forkedForEmbedded(FeatureSpecGenerator.java:232)
at org.wildfly.galleon.plugin.server.ForkedEmbeddedUtil.main(ForkedEmbeddedUtil.java:204)
java.lang.Exception: WFLYSRV0056: Server boot has failed in an unrecoverable manner; exiting. See previous messages for details.
at org.jboss.as.server.BootstrapListener.bootFailure(BootstrapListener.java:87)
at org.jboss.as.server.ServerService.boot(ServerService.java:407)
at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:372)
at java.lang.Thread.run(Thread.java:748)

or

Downloaded from jboss-eap-7.2-product-repository: http://download.eng.bos.redhat.com/brewroot/repos/jb-eap-7.2-maven-build/latest/maven/org/jboss/jboss-parent/28.0.0.redhat-00001/jboss-parent-28.0.0.redhat-00001.pom (0 B at 0 B/s)
[ERROR] [ERROR] Some problems were encountered while processing the POMs:
[ERROR] Resolving expression: '${version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64}': Detected the following recursive expression cycle in 'version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64': [version.org.wildfly.openssl.wildfly
-openssl-macosx-x86_64] @ org.jboss.eap:wildfly-component-matrix:7.2.2.GA-redhat-SNAPSHOT
[ERROR] Resolving expression: '${version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64}': Detected the following recursive expression cycle in 'version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64': [version.org.wildfly.openssl.wildfly
-openssl-macosx-x86_64] @ org.jboss.eap:wildfly-component-matrix:7.2.2.GA-redhat-SNAPSHOT
[ERROR] 'dependencies.dependency.version' for org.wildfly.arquillian:wildfly-arquillian-container-managed:jar is missing. @ line 165, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.shrinkwrap:shrinkwrap-api:jar is missing. @ line 169, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.eap:wildfly-testsuite-shared:jar is missing. @ line 174, column 29
[ERROR] 'dependencies.dependency.version' for org.wildfly.core:wildfly-core-testsuite-shared:jar is missing. @ line 179, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.arquillian.junit:arquillian-junit-container:jar is missing. @ line 184, column 29
[ERROR] 'dependencies.dependency.version' for org.apache.httpcomponents:httpclient:jar is missing. @ line 188, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.spec.javax.servlet:jboss-servlet-api_3.1_spec:jar is missing. @ line 192, column 29
[ERROR] 'dependencies.dependency.version' for junit:junit:jar is missing. @ line 216, column 29
@
[ERROR] The build could not read 1 project -> [Help 1]
[ERROR]
[ERROR] The project org.jboss:eap72x-proposed-additional-testsuite:1.0.3.Final (/tmp/tmp.rbNaaYxrYE/modules/testcases/jdkAll/Eap72x-Proposed/pom.xml) has 10 errors
[ERROR] Resolving expression: '${version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64}': Detected the following recursive expression cycle in 'version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64': [version.org.wildfly.openssl.wil
dfly-openssl-macosx-x86_64] @ org.jboss.eap:wildfly-component-matrix:7.2.2.GA-redhat-SNAPSHOT -> [Help 2]
[ERROR] Resolving expression: '${version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64}': Detected the following recursive expression cycle in 'version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64': [version.org.wildfly.openssl.wil
dfly-openssl-macosx-x86_64] @ org.jboss.eap:wildfly-component-matrix:7.2.2.GA-redhat-SNAPSHOT -> [Help 2]
[ERROR] 'dependencies.dependency.version' for org.wildfly.arquillian:wildfly-arquillian-container-managed:jar is missing. @ line 165, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.shrinkwrap:shrinkwrap-api:jar is missing. @ line 169, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.eap:wildfly-testsuite-shared:jar is missing. @ line 174, column 29
[ERROR] 'dependencies.dependency.version' for org.wildfly.core:wildfly-core-testsuite-shared:jar is missing. @ line 179, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.arquillian.junit:arquillian-junit-container:jar is missing. @ line 184, column 29
[ERROR] 'dependencies.dependency.version' for org.apache.httpcomponents:httpclient:jar is missing. @ line 188, column 29
[ERROR] 'dependencies.dependency.version' for org.jboss.spec.javax.servlet:jboss-servlet-api_3.1_spec:jar is missing. @ line 192, column 29
[ERROR] 'dependencies.dependency.version' for junit:junit:jar is missing. @ line 216, column 29
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/ProjectBuildingException
[ERROR] [Help 2] http://cwiki.apache.org/confluence/display/MAVEN/InterpolationCycleException

Pom generated from component-matrix has:

maven-local-repository/org/jboss/eap/wildfly-component-matrix/7.2.2.GA-redhat-SNAPSHOT/wildfly-component-matrix-7.2.2.GA-redhat-SNAPSHOT.pom: <version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64>${version.org.wildfly.openssl.wildfly-op
enssl-macosx-x86_64}</version.org.wildfly.openssl.wildfly-openssl-macosx-x86_64>