# HG changeset patch
# User wenzelm
# Date 1544111320 -3600
# Node ID 99c3529c31d0daf5e6a8089026f0da388f44ebec
# Parent  eab0d3108b46fd55f423ed78e929396e409c0307
clarified error;

diff -r eab0d3108b46 -r 99c3529c31d0 src/Pure/Admin/build_release.scala
--- a/src/Pure/Admin/build_release.scala	Thu Dec 06 16:40:56 2018 +0100
+++ b/src/Pure/Admin/build_release.scala	Thu Dec 06 16:48:40 2018 +0100
@@ -226,7 +226,7 @@
   private def tar_options: String =
     if (Platform.is_macos) "--owner=root --group=staff" else "--owner=root --group=root"
 
-  private val default_platform_families =
+  private val default_platform_families: List[Platform.Family.Value] =
     List(Platform.Family.linux, Platform.Family.windows, Platform.Family.macos)
 
   def build_release(base_dir: Path,
@@ -792,6 +792,9 @@
 
       val progress = new Console_Progress()
 
+      if (platform_families.contains(Platform.Family.windows) && !Isabelle_System.bash("7z i").ok)
+        error("Building for windows requires 7z")
+
       build_release(Path.explode(base_dir), options, components_base = components_base,
         progress = progress, rev = rev, afp_rev = afp_rev, official_release = official_release,
         proper_release_name = proper_release_name, website = website,