allow to override repository versions at runtime;

--- a/etc/options	Fri Feb 07 20:26:31 2020 +0100
+++ b/etc/options	Sat Feb 08 15:18:58 2020 +0100
@@ -283,6 +283,18 @@
   -- "maximum number of messages to keep SSH server connection alive"
 
 
+section "Phabricator"
+
+option phabricator_version_arcanist : string = "729100955129851a52588cdfd9b425197cf05815"
+  -- "repository version for arcanist"
+
+option phabricator_version_libphutil : string = "034cf7cc39940b935e83923dbb1bacbcfe645a85"
+  -- "repository version for libphutil"
+
+option phabricator_version_phabricator : string = "46fcd135ae681bb90a1282114fb2147ab21e4f34"
+  -- "repository version for phabricator"
+
+
 section "Theory Export"
 
 option export_document : bool = false

--- a/src/Doc/System/Phabricator.thy	Fri Feb 07 20:26:31 2020 +0100
+++ b/src/Doc/System/Phabricator.thy	Sat Feb 08 15:18:58 2020 +0100
@@ -398,6 +398,7 @@
     -R DIR       repository directory (default: "/var/www/phabricator-NAME/repo")
     -U           full update of system packages before installation
     -n NAME      Phabricator installation name (default: "vcs")
+    -o OPTION    override Isabelle system OPTION (via NAME=VAL or NAME)
     -r DIR       installation root directory (default: "/var/www/phabricator-NAME")
 
   Install Phabricator as LAMP application (Linux, Apache, MySQL, PHP).
@@ -438,6 +439,10 @@
   also uses the same suffix, but that can (and should) be changed later via
   regular Apache configuration.
 
+  Option \<^verbatim>\<open>-o\<close> augments the environment of Isabelle system options: relevant
+  options for Isabelle/Phabricator have the prefix ``\<^verbatim>\<open>phabricator_\<close>'' (see
+  also the result of e.g. ``\<^verbatim>\<open>isabelle options -l\<close>'').
+
   Option \<^verbatim>\<open>-r\<close> specifies an alternative installation root directory: it needs
   to be accessible for the Apache web server.
 

--- a/src/Pure/Tools/phabricator.scala	Fri Feb 07 20:26:31 2020 +0100
+++ b/src/Pure/Tools/phabricator.scala	Sat Feb 08 15:18:58 2020 +0100
@@ -220,6 +220,7 @@
   }
 
   def phabricator_setup(
+    options: Options,
     name: String = default_name,
     root: String = "",
     repo: String = "",
@@ -287,14 +288,17 @@
         set -e
         echo "Cloning distribution repositories:"
 
-        git clone --branch stable https://github.com/phacility/libphutil.git
-        git -C libphutil reset --hard 034cf7cc39940b935e83923dbb1bacbcfe645a85
+        git clone --branch stable https://github.com/phacility/arcanist.git
+        git -C arcanist reset --hard """ +
+          Bash.string(options.string("phabricator_version_arcanist")) + """
 
-        git clone --branch stable https://github.com/phacility/arcanist.git
-        git -C arcanist reset --hard 729100955129851a52588cdfd9b425197cf05815
+        git clone --branch stable https://github.com/phacility/libphutil.git
+        git -C libphutil reset --hard """ +
+          Bash.string(options.string("phabricator_version_libphutil")) + """
 
         git clone --branch stable https://github.com/phacility/phabricator.git
-        git -C phabricator reset --hard 46fcd135ae681bb90a1282114fb2147ab21e4f34
+        git -C phabricator reset --hard """ +
+          Bash.string(options.string("phabricator_version_phabricator")) + """
       """).check
 
     val config = Config(name, root_path)
@@ -529,6 +533,7 @@
       var repo = ""
       var package_update = false
       var name = default_name
+      var options = Options.init()
       var root = ""
 
       val getopts =
@@ -541,6 +546,7 @@
     -R DIR       repository directory (default: """ + default_repo("NAME") + """)
     -U           full update of system packages before installation
     -n NAME      Phabricator installation name (default: """ + quote(default_name) + """)
+    -o OPTION    override Isabelle system OPTION (via NAME=VAL or NAME)
     -r DIR       installation root directory (default: """ + default_root("NAME") + """)
 
   Install Phabricator as LAMP application (Linux, Apache, MySQL, PHP).
@@ -552,6 +558,7 @@
           "R:" -> (arg => repo = arg),
           "U" -> (_ => package_update = true),
           "n:" -> (arg => name = arg),
+          "o:" -> (arg => options = options + arg),
           "r:" -> (arg => root = arg))
 
       val more_args = getopts(args)
@@ -562,7 +569,7 @@
       val release = Linux.Release()
       if (!release.is_ubuntu_18_04) error("Bad Linux version: Ubuntu 18.04 LTS required")
 
-      phabricator_setup(name = name, root = root, repo = repo,
+      phabricator_setup(options, name = name, root = root, repo = repo,
         package_update = package_update, mercurial_source = mercurial_source, progress = progress)
     })