我们有一个带有 TeamCity 和 subversion 的持续集成环境设置。TeamCity 从 svn 获取最新源代码，并在每次提交时进行构建（Visual Studio）。
有时在构建运行时我们会收到以下 TeamCity 错误。进行几次强制构建可使 TeamCity 成功运行。
**Build errors
[12:35:24]: Patch is broken, can be found in file: C:\TeamCity\buildAgent\temp\cache\temp6036patch_803[12:35:24]: RunBuildException when running build stage UpdateSourcesFromServer: Failed to build patch for build 519 {build id=803}, VCS root: svn: https://svn.myDomain.com/repos/myApplication {id=2}, due to error: org.tmatesoft.svn.core.SVNException: svn: connection refused by the server
svn: REPORT request failed on '/repos/myApplication/!svn/vcc/default'**
任何想法为什么会发生这种情况？
这是构建日志的一部分
[12:58:39]: [Updating sources: server side checkout...] Transferring cached clean patch for VCS root: [svn url]
[12:58:40]: [Updating sources: server side checkout...] Building incremental patch over the cached patch
[12:59:30]: [Updating sources: server side checkout...] Failed to build patch for build 146 {build id=806}, VCS root: svn: [svn url]{id=2}, due to error: org.tmatesoft.svn.core.SVNException: svn: connection refused by the server
svn: REPORT request failed on '[svn url]!svn/vcc/default'
[12:59:30]: [Updating sources: server side checkout...] Repository sources transferred: 14.08Mb total
[12:59:30]: [Updating sources: server side checkout...] Average transfer speed: 280.89Kb per second
[12:59:30]: Will repeat attempt when server will be available, number of attempts left: 2
[12:59:40]: Updating sources: server side checkout...
jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl$1: Server was not able to build correct patch, most likely due to VCS errors, will try again.
jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl$1: Server was not able to build correct patch, most likely due to VCS errors, will try again.
at jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl.throwError(PatchDownloaderImpl.java:113)
at jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl.checkPatch(PatchDownloaderImpl.java:103)
at jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl.copyPatchAndCheck(PatchDownloaderImpl.java:64)
at jetbrains.buildServer.agent.impl.patch.UpdateSourcesPatcherBase.copyPatchToTempFile(UpdateSourcesPatcherBase.java:65)
at jetbrains.buildServer.agent.impl.patch.UpdateSourcesFromServer.updateSources(UpdateSourcesFromServer.java:58)
at jetbrains.buildServer.agent.impl.patch.UpdateSourcesBuildStageBase.doSourceUpdate(UpdateSourcesBuildStageBase.java:74)
at jetbrains.buildServer.agent.impl.patch.UpdateSourcesBuildStageBase.doRecoverableStage(UpdateSourcesBuildStageBase.java:52)
at jetbrains.buildServer.agent.impl.runStages.RecoverableBuildStage.doLastAttempt(RecoverableBuildStage.java:101)
at jetbrains.buildServer.agent.impl.runStages.RecoverableBuildStage.doBuildStage(RecoverableBuildStage.java:58)
at jetbrains.buildServer.agent.impl.BuildRunAction.callRunStage(BuildRunAction.java:119)
at jetbrains.buildServer.agent.impl.BuildRunAction.doStages(BuildRunAction.java:83)
at jetbrains.buildServer.agent.impl.BuildRunAction.access$000(BuildRunAction.java:18)
at jetbrains.buildServer.agent.impl.BuildRunAction$1.run(BuildRunAction.java:56)
at java.lang.Thread.run(Thread.java:595)
Caused by: jetbrains.buildServer.vcs.patches.UnsuccessfulPatchException: Failed to build patch for build 146 {build id=806}, VCS root: svn: [svn url]{id=2}, due to error: org.tmatesoft.svn.core.SVNException: svn: connection refused by the server
svn: REPORT request failed on '[svn url]!svn/vcc/default'
at jetbrains.buildServer.vcs.patches.AbstractPatcher$1.fail(AbstractPatcher.java:93)
at jetbrains.buildServer.vcs.patches.LowLevelPatcher.readPatchStream(LowLevelPatcher.java:156)
at jetbrains.buildServer.vcs.patches.LowLevelPatcher.applyPatch(LowLevelPatcher.java:79)
at jetbrains.buildServer.vcs.patches.AbstractPatcher.applyPatch(AbstractPatcher.java:42)
at jetbrains.buildServer.agent.impl.patch.PatchApplierImpl.applyPatch(PatchApplierImpl.java:18)
at jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl.checkPatchInFileIsCompleted(PatchDownloaderImpl.java:83)
at jetbrains.buildServer.agent.impl.patch.PatchDownloaderImpl.checkPatch(PatchDownloaderImpl.java:93)
... 12 more