I’m using TeamCity, MSBuild, and SVN together to do some pretty cool stuff around continuous integration and automated builds.  It’s been working well, untouched, for well over a year!  But all of a sudden my deployment process failed. Checking the logs with TeamCity, I found this:

[11:18:06]:   Error validating server certificate for 'https://[xxx].com:443':
[11:18:06]:    - The certificate is not issued by a trusted authority. Use the
[11:18:06]:      fingerprint to validate the certificate manually!
[11:18:06]:   Certificate information:
[11:18:06]:    - Hostname: [xxx]
[11:18:06]:    - Valid: from Mon, 29 Mar 2010 17:44:04 GMT until Thu, 26 Mar 2020 17:44:04 GMT
[11:18:06]:    - Issuer: [xxx]
[11:18:06]:    - Fingerprint: [xxx]
[11:18:06]:   (R)eject, accept (t)emporarily or accept (p)ermanently? svn: OPTIONS of 'https://[xxx]': Server certificate verification failed: issuer is not trusted (https://[xxx].com)

The best part about this was that, for a change, this error message was very clear.  Although I don’t know why the certificate failed.  Did it change or expire?  Did one of the network guys make a change to something?  I didn’t really care.  I just wanted to get my build working again.

Here is the line of MSBuild Script that caused the issue: (I’m using the SVN stuff from MSBuild Community Tasks)

<SvnClient Command="ls $(SvnRepository)/tags/$(BuildNumber) Username="$(SvnUserName)" password="$(SvnPassword)" ContinueOnError="true">
  <Output TaskParameter="ExitCode" PropertyName="Value"/>
</SvnClient>

Since the Command of SvnClient accepts any SVN command (in other words, anything that I can type at a command prompt), I searched the SVN Documentation.  It wasn’t hard to find that I just needed to update to this:

<SvnClient Command="ls $(SvnRepository)/tags/$(BuildNumber) --non-interactive --trust-server-cert" Username="$(SvnUserName)" password="$(SvnPassword)" ContinueOnError="true">
  <Output TaskParameter="ExitCode" PropertyName="Value"/>
</SvnClient>

This worked great but my build still failed.  That is because I have other SVN actions in my script and they don’t seem to know that I accepted the certificate. However, my other tasks are not using the very generic and flexible SvnClient Command, they are using tasks such as SvnCopy or SvnCommit, etc.  For instance:

<SvnCopy SourcePath="$(SvnRepository)/$(SvnProjectLocation)/"
    DestinationPath="$(SvnRepository)/tags/$(BuildNumber)"
    Message="Auto-tagging Revision: $(BuildNumber)"
    Username="$(SvnUserName)" password="$(SvnPassword)" />

So how could I tell SVN to accept the certificate.  I checked the MSBuild Community Tasks documentation, took a guess and got lucky on the first try…sweet.  I added this:

    <SvnCopy SourcePath="$(SvnRepository)/$(SvnProjectLocation)/"
        DestinationPath="$(SvnRepository)/tags/$(BuildNumber)"
        Message="Auto-tagging Revision: $(BuildNumber)"
        Username="$(SvnUserName)" password="$(SvnPassword)"
        Arguments="--non-interactive --trust-server-cert" />

I added the Arguments to all of my other SVN Tasks in my script and it worked perfectly!