# HG changeset patch
# User wenzelm
# Date 1607799766 -3600
# Node ID 6751057a64b1d459780a6cf4549f5dbd5bcfd5a3
# Parent  42d75bf8725cbc48a33c9840259cf57550db560c
purge build dir;

diff -r 42d75bf8725c -r 6751057a64b1 src/Pure/Admin/build_vampire.scala
--- a/src/Pure/Admin/build_vampire.scala	Sat Dec 12 19:25:42 2020 +0100
+++ b/src/Pure/Admin/build_vampire.scala	Sat Dec 12 20:02:46 2020 +0100
@@ -61,7 +61,9 @@
         progress.bash("git checkout --quiet --detach " + Bash.string(rev),
           cwd = source_dir.file, echo = verbose).check
 
-        val build_dir = Isabelle_System.make_directory(source_dir + Path.explode("build"))
+        val build_dir = source_dir + Path.explode("build")
+        Isabelle_System.rm_tree(build_dir)
+        Isabelle_System.make_directory(build_dir)
 
         val cmake_opts = if (Platform.is_linux) "-DBUILD_SHARED_LIBS=0 " else ""
         val cmake_out =