If is not absolute path in data-uri() funciton, the plugin cant found it, because it works with /tmp/file.less copy.
If is absolute path, it also not works:
Compiling LESS source: viewer_dark.less...
/home/***/src/main/java/../webapp/less/main/viewer_dark.less [0:0]: Error compiling LESS source
org.lesscss.LessException: RuntimeError: error evaluating function `data-uri`: Cannot convert org.mozilla.javascript.NativeArray@103af23c to byte[] (jar:file:/home/***/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js#145) in /tmp/tmp6500585619073531749less.tmp on line 382, column 44:
381
382 .pv-clear-all,.pv-cat-clear{background:data-uri("@{embedImgBase}/clear.png") no-repeat 50% 50%;}
383 .pv-clear-all{width:60px; margin:0 0 4px 0; padding:0 5px; line-height:24px; float:right; color:@color-control-text-dark2; background-position:54px 50% ;visibility:hidden;}
at org.lesscss.LessCompiler.compile(LessCompiler.java:423)
at org.lesscss.LessCompiler.compile(LessCompiler.java:330)
at org.lesscss.LessCompiler.compile(LessCompiler.java:474)
at org.lesscss.LessCompiler.compile(LessCompiler.java:498)
at org.lesscss.mojo.CompileMojo.compileIfChanged(CompileMojo.java:187)
at org.lesscss.mojo.CompileMojo.executeInternal(CompileMojo.java:157)
at org.lesscss.mojo.CompileMojo.execute(CompileMojo.java:122)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.mozilla.javascript.JavaScriptException: Error: RuntimeError: error evaluating function `data-uri`: Cannot convert org.mozilla.javascript.NativeArray@103af23c to byte[] (jar:file:/home/***/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js#145) in /tmp/tmp6500585619073531749less.tmp on line 382, column 44:
381
382 .pv-clear-all,.pv-cat-clear{background:data-uri("@{embedImgBase}/clear.png") no-repeat 50% 50%;}
383 .pv-clear-all{width:60px; margin:0 0 4px 0; padding:0 5px; line-height:24px; float:right; color:@color-control-text-dark2; background-position:54px 50% ;visibility:hidden;}
(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js#9361)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1._c_writeError_660(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js:9361)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1.call(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js)
at org.mozilla.javascript.optimizer.OptRuntime.callName(OptRuntime.java:63)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1._c_anonymous_665(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js:9746)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1.call(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js)
at org.mozilla.javascript.optimizer.OptRuntime.call1(OptRuntime.java:32)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1._c_script_0(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js:9448)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1.call(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js)
at org.mozilla.javascript.ContextFactory.doTopCall(ContextFactory.java:394)
at org.mozilla.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3091)
at org.mozilla.javascript.gen.jar_file__home_accelerate__m2_repository_org_lesscss_lesscss_1_7_0_1_1_lesscss_1_7_0_1_1_jar__META_INF_less_rhino_1_7_0_js_1.call(jar:file:/home/accelerate/.m2/repository/org/lesscss/lesscss/1.7.0.1.1/lesscss-1.7.0.1.1.jar!/META-INF/less-rhino-1.7.0.js)
at org.lesscss.LessCompiler.compile(LessCompiler.java:383)
... 27 more
------------------------------------------------------------------------
BUILD FAILURE