Checks if tool is installed (svn, cvs, hg)

3 files changed, 15 insertions, 2 deletions

diff --git a/src/luarocks/fetch/cvs.lua b/src/luarocks/fetch/cvs.lua
index cc9fd655..fad1ca0d 100644
--- a/src/luarocks/fetch/cvs.lua
+++ b/src/luarocks/fetch/cvs.lua
@@ -20,9 +20,14 @@ function cvs.get_sources(rockspec, extract, dest_dir)
    assert(type(rockspec) == "table")
    assert(type(dest_dir) == "string" or not dest_dir)
 
+   local cvs_cmd = rockspec.variables.CVS
+   if not fs.execute_quiet(cvs_cmd, "--version") then
+      return nil, "'"..cvs_cmd.."' program not found. Is CVS installed? You may want to edit variables.CVS"
+   end
+
    local name_version = rockspec.name .. "-" .. rockspec.version
    local module = rockspec.source.module or dir.base_name(rockspec.source.url)
-   local command = {rockspec.variables.CVS, "-d"..rockspec.source.pathname, "export", module}
+   local command = {cvs_cmd, "-d"..rockspec.source.pathname, "export", module}
    if rockspec.source.tag then
       table.insert(command, 4, "-r")
       table.insert(command, 5, rockspec.source.tag)
diff --git a/src/luarocks/fetch/hg.lua b/src/luarocks/fetch/hg.lua
index e736a071..055e3bbe 100644
--- a/src/luarocks/fetch/hg.lua
+++ b/src/luarocks/fetch/hg.lua
@@ -21,9 +21,13 @@ function hg.get_sources(rockspec, extract, dest_dir)
    assert(type(dest_dir) == "string" or not dest_dir)
 
    local hg_cmd = rockspec.variables.HG
+   if not fs.execute_quiet(hg_cmd, "--version") then
+      return nil, "'"..hg_cmd.."' program not found. Is Mercurial installed? You may want to edit variables.HG"
+   end
+
    local name_version = rockspec.name .. "-" .. rockspec.version
    -- Strip off special hg:// protocol type
-   local url = rockspec.source.url:gsub("^hg://", "") 
+   local url = rockspec.source.url:gsub("^hg://", "")
 
    local module = dir.base_name(url)
 
diff --git a/src/luarocks/fetch/svn.lua b/src/luarocks/fetch/svn.lua
index abeacf9a..8fe582f6 100644
--- a/src/luarocks/fetch/svn.lua
+++ b/src/luarocks/fetch/svn.lua
@@ -21,6 +21,10 @@ function svn.get_sources(rockspec, extract, dest_dir)
    assert(type(dest_dir) == "string" or not dest_dir)
 
    local svn_cmd = rockspec.variables.SVN
+   if not fs.execute_quiet(svn_cmd, "--version") then
+      return nil, "'"..svn_cmd.."' program not found. Is Subversion installed? You may want to edit variables.SVN"
+   end
+
    local name_version = rockspec.name .. "-" .. rockspec.version
    local module = rockspec.source.module or dir.base_name(rockspec.source.url)
    local url = rockspec.source.url:gsub("^svn://", "")