diff --git a/waflib/Tools/c_config.py b/waflib/Tools/c_config.py
index 14243cd8..cb7e30ed 100644
--- a/waflib/Tools/c_config.py
+++ b/waflib/Tools/c_config.py
@@ -6,7 +6,7 @@
 C/C++/D configuration helpers
 """
 
-import os, re, shlex, sys
+import os, re, shlex
 from waflib import Build, Utils, Task, Options, Logs, Errors, Runner
 from waflib.TaskGen import after_method, feature
 from waflib.Configure import conf
@@ -288,7 +288,7 @@ def exec_cfg(self, kw):
 	"""
 
 	path = Utils.to_list(kw['path'])
-
+	env = self.env.env or None
 	def define_it():
 		pkgname = kw.get('uselib_store', kw['package'].upper())
 		if kw.get('global_define'):
@@ -301,7 +301,7 @@ def exec_cfg(self, kw):
 	# pkg-config version
 	if 'atleast_pkgconfig_version' in kw:
 		cmd = path + ['--atleast-pkgconfig-version=%s' % kw['atleast_pkgconfig_version']]
-		self.cmd_and_log(cmd)
+		self.cmd_and_log(cmd, env=env)
 		if not 'okmsg' in kw:
 			kw['okmsg'] = 'yes'
 		return
@@ -310,7 +310,7 @@ def exec_cfg(self, kw):
 	for x in cfg_ver:
 		y = x.replace('-', '_')
 		if y in kw:
-			self.cmd_and_log(path + ['--%s=%s' % (x, kw[y]), kw['package']])
+			self.cmd_and_log(path + ['--%s=%s' % (x, kw[y]), kw['package']], env=env)
 			if not 'okmsg' in kw:
 				kw['okmsg'] = 'yes'
 			define_it()
@@ -318,7 +318,7 @@ def exec_cfg(self, kw):
 
 	# retrieving the version of a module
 	if 'modversion' in kw:
-		version = self.cmd_and_log(path + ['--modversion', kw['modversion']]).strip()
+		version = self.cmd_and_log(path + ['--modversion', kw['modversion']], env=env).strip()
 		self.define('%s_VERSION' % Utils.quote_define_name(kw.get('uselib_store', kw['modversion'])), version)
 		return version
 
@@ -342,19 +342,19 @@ def exec_cfg(self, kw):
 
 	# retrieving variables of a module
 	if 'variables' in kw:
-		env = kw.get('env', self.env)
+		v = kw.get('env', self.env)
 		uselib = kw.get('uselib_store', kw['package'].upper())
 		vars = Utils.to_list(kw['variables'])
 		for v in vars:
-			val = self.cmd_and_log(lst + ['--variable=' + v]).strip()
+			val = self.cmd_and_log(lst + ['--variable=' + v], env=env).strip()
 			var = '%s_%s' % (uselib, v)
-			env[var] = val
+			v[var] = val
 		if not 'okmsg' in kw:
 			kw['okmsg'] = 'yes'
 		return
 
 	# so we assume the command-line will output flags to be parsed afterwards
-	ret = self.cmd_and_log(lst)
+	ret = self.cmd_and_log(lst, env=env)
 	if not 'okmsg' in kw:
 		kw['okmsg'] = 'yes'