C++ stdlib check: don't check executables for deps

This avoids some possible false positives, as happens with, e.g., qt4.

1 files changed, 10 insertions, 0 deletions

diff --git a/Library/Homebrew/build.rb b/Library/Homebrew/build.rb
index 7db2235ed..83dbe15cb 100755
--- a/Library/Homebrew/build.rb
+++ b/Library/Homebrew/build.rb
@@ -164,6 +164,9 @@ class Build
         begin
           f.install
 
+          # This first test includes executables because we still
+          # want to record the stdlib for something that installs no
+          # dylibs.
           stdlibs = Keg.new(f.prefix).detect_cxx_stdlibs
           # It's technically possible for the same lib to link to multiple
           # C++ stdlibs, but very bad news. Right now we don't track this
@@ -173,6 +176,13 @@ class Build
           # incompatibility.
           stdlib_in_use.check_dependencies(f, deps)
 
+          # This second check is recorded for checking dependencies,
+          # so executable are irrelevant at this point. If a piece
+          # of software installs an executable that links against libstdc++
+          # and dylibs against libc++, libc++-only dependencies can safely
+          # link against it.
+          stdlibs = Keg.new(f.prefix).detect_cxx_stdlibs :skip_executables => true
+
           Tab.create(f, ENV.compiler, stdlibs.first,
             Options.coerce(ARGV.options_only)).write
         rescue Exception => e