Exclude pre-release tags from PDF builds (#3)

Author: mortenpi

pdf/make.jl

@@ -121,7 +121,9 @@ function collect_versions()
         # lines are in the form 'COMMITSHA\trefs/tags/TAG'
         _, ref = split(line, '\t')
         _, _, tag = split(ref, '/')
-        if occursin(Base.VERSION_REGEX, tag)
+        if occursin(r"^v\d+\.\d+\.\d+$", tag)
+            # the version regex is not as general as Base.VERSION_REGEX -- we only build "pure"
+            # versions and exclude tags that are pre-releases or have build information.
             v = VersionNumber(tag)
             # pdf doc only possible for 1.0.3 and above
             v >= v"1.0.4" && push!(versions, v)