see http://petabridge-ci.cloudapp.net/viewLog.html?buildId=27552&buildTypeId=AkkaNet_AkkaNetLinuxMonoUnitTests&guest=1

(from pr akkadotnet/akka.net#2714)

Please note that I have spent zero time analyzing this.

[08:40:13] at Microsoft.FSharp.Compiler.Interactive.Shell+FsiEvaluationSession.EvalScript (System.String filePath) [0x00001] in <566ee2a1ddab8ea7a7450383a1e26e56>:0
[08:40:13] at Yaaf.FSharp.Scripting.Helper+evalScript@1097.Invoke (System.String arg00) [0x00001] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Yaaf.FSharp.Scripting.Helper+saveScript@1090-1[a].Invoke (System.String path) [0x00033] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Yaaf.FSharp.Scripting.Helper+save_@1072-2[a].Invoke (Microsoft.FSharp.Core.Unit unitVar0) [0x00001] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Yaaf.FSharp.Scripting.Helper.consoleCapture[a] (System.IO.TextWriter out, System.IO.TextWriter err, Microsoft.FSharp.Core.FSharpFunc2[T,TResult] f) [0x0001a] in <56a0916bccf1c534a74503836b91a056>:0 [08:40:13] at Yaaf.FSharp.Scripting.Helper.redirectOut@1044[a] (System.Boolean preventStdOut, Yaaf.FSharp.Scripting.Helper+OutStreamHelper out, Yaaf.FSharp.Scripting.Helper+OutStreamHelper err, Microsoft.FSharp.Core.FSharpFunc2[T,TResult] f) [0x0006e] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Yaaf.FSharp.Scripting.Helper+save_@1071-1[a].Invoke (System.String text) [0x0002c] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] --- End of inner exception stack trace ---
[08:40:13] at Yaaf.FSharp.Scripting.Helper+save_@1071-1[a].Invoke (System.String text) [0x0008e] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Yaaf.FSharp.Scripting.Helper+session@1100.Yaaf-FSharp-Scripting-IFsiSession-EvalScriptWithOutput (System.String ) [0x00001] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Fake.FSIHelper.runFAKEScriptWithFsiArgsAndRedirectMessages$cont@365 (System.Boolean printDetails, System.Boolean useCache, System.Boolean cleanCache, Yaaf.FSharp.Scripting.FsiOptions options, System.String scriptPath, Fake.FSIHelper+CacheInfo cacheInfo, System.String wishName, System.IO.TextWriter out, System.IO.TextWriter err, Microsoft.FSharp.Core.Unit unitVar) [0x00172] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13]error FS0193: Specified method is not supported.
[08:40:13]
[08:40:13]CACHING ERROR (please open a issue on FAKE and /cc @matthid): System.NotSupportedException: Type 'FSI_0005.Build' was not completed.
[08:40:13] at System.Reflection.Emit.ModuleBuilder.Save () [0x00048] in <4dc8ec68b0964e099af86e50301f5f3c>:0
[08:40:13] at System.Reflection.Emit.AssemblyBuilder.Save (System.String assemblyFileName, System.Reflection.PortableExecutableKinds portableExecutableKind, System.Reflection.ImageFileMachine imageFileMachine) [0x0022b] in <4dc8ec68b0964e099af86e50301f5f3c>:0
[08:40:13] at System.Reflection.Emit.AssemblyBuilder.Save (System.String assemblyFileName) [0x00000] in <4dc8ec68b0964e099af86e50301f5f3c>:0
[08:40:13] at Fake.FSIHelper.runFAKEScriptWithFsiArgsAndRedirectMessages$cont@415-1 (System.Boolean printDetails, Fake.FSIHelper+CacheInfo cacheInfo, System.String wishName, System.IO.DirectoryInfo cacheDir, System.Text.StringBuilder fsiErrorOutput, Yaaf.FSharp.Scripting.IFsiSession session, Microsoft.FSharp.Core.Unit unitVar) [0x00019] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:13] at Fake.FSIHelper.runFAKEScriptWithFsiArgsAndRedirectMessages$cont@365 (System.Boolean printDetails, System.Boolean useCache, System.Boolean cleanCache, Yaaf.FSharp.Scripting.FsiOptions options, System.String scriptPath, Fake.FSIHelper+CacheInfo cacheInfo, System.String wishName, System.IO.TextWriter out, System.IO.TextWriter err, Microsoft.FSharp.Core.Unit unitVar) [0x001f1] in <56a0916bccf1c534a74503836b91a056>:0
[08:40:14]Process exited with code 1