linux26 target can be used for Linux 2.6 and above.

component/haproxy/buildout.cfg

@@ -10,6 +10,6 @@ configure-command = true
 # otherwise use "generic".
 # For ARCH value, x86_64 and i[3456]86 are supported.
 make-options =
-  TARGET="$(uname -sr 2>/dev/null|grep -q '^Linux 2\.6' && echo linux26 || echo generic)"
+  TARGET="$(uname -sr 2>/dev/null|grep -E '^Linux (2\.6|3) && echo linux26 || echo generic)"
   ARCH="$(uname -m 2>/dev/null|grep -E '^(x86_64|i[3456]86)$')"
   PREFIX=${buildout:parts-directory}/${:_buildout_section_name_}