Replace [^a-zA-Z0-9-] with - in BranchName variable. Otherwise the branch name variable can never be used in any SemVer spec since it can contain a / when using nested branches.

Author: KiLLeRRaT

src/GitVersionCore/SemanticVersioning/SemanticVersionFormatValues.cs

@@ -51,7 +51,7 @@ public SemanticVersionFormatValues(SemanticVersion semver, EffectiveConfiguratio
 
         public string FullSemVer => semver.ToString("f");
 
-        public string BranchName => semver.BuildMetaData.Branch;
+        public string BranchName => semver.BuildMetaData.Branch.RegexReplace("[^a-zA-Z0-9-]", "-");
 
         public string Sha => semver.BuildMetaData.Sha;