Merge branch 'adamjstewart-features/libsigsegv' into develop

var/spack/repos/builtin/packages/libsigsegv/package.py

@@ -0,0 +1,15 @@
+from spack import *
+
+class Libsigsegv(Package):
+    """GNU libsigsegv is a library for handling page faults in user mode."""
+    homepage = "https://www.gnu.org/software/libsigsegv/"
+    url      = "ftp://ftp.gnu.org/gnu/libsigsegv/libsigsegv-2.10.tar.gz"
+
+    version('2.10', '7f96fb1f65b3b8cbc1582fb7be774f0f')
+
+    def install(self, spec, prefix):
+        configure('--prefix=%s' % prefix,
+                  '--enable-shared')
+
+        make()
+        make("install")

var/spack/repos/builtin/packages/m4/package.py

@@ -7,7 +7,17 @@ class M4(Package):
 
     version('1.4.17', 'a5e9954b1dae036762f7b13673a2cf76')
 
+    variant('sigsegv', default=True, description="Build the libsigsegv dependency")
+
+    depends_on('libsigsegv', when='+sigsegv')
+
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix)
+        configure_args = []
+        if 'libsigsegv' in spec:
+            configure_args.append('--with-libsigsegv-prefix=%s' % spec['libsigsegv'].prefix)
+        else:
+            configure_args.append('--without-libsigsegv-prefix')
+
+        configure("--prefix=%s" % prefix, *configure_args)
         make()
         make("install")