diff --git a/src/bot/precompile_include.jl b/src/bot/precompile_include.jl
index fad351338..53a892bfc 100644
--- a/src/bot/precompile_include.jl
+++ b/src/bot/precompile_include.jl
@@ -14,12 +14,17 @@ allos_funs = [
          Sys.isnetbsd,
          Sys.isopenbsd,
          Sys.isjsvm]
+    os = ""
+    osfun = allos_funs[1] # temp
     for osfun in allos_funs
         if osfun()
             os = string(osfun)[3:end]
             break
         end
     end
+    if os == ""
+        @error "os is not detected"
+    end
     return os, osfun
 end
 ################################################################