Fix UT on ubuntu

test/popen_unittest.cpp

@@ -3,11 +3,10 @@
 // Author: Zhangyi Chen (chenzhangyi01@baidu.com)
 // Date: 2017/11/06 10:57:08
 
-#include <gtest/gtest.h>
-#include <sstream>
 #include "butil/popen.h"
 #include "butil/errno.h"
 #include "butil/strings/string_piece.h"
+#include <gtest/gtest.h>
 
 namespace {
 
@@ -23,7 +22,7 @@ TEST(PopenTest, sanity) {
     oss.str("");
     rc = butil::read_command_output(oss, "exit 1");
     ASSERT_EQ(1, rc) << berror(errno);
-    ASSERT_TRUE(oss.str().empty()) << oss;
+    ASSERT_TRUE(oss.str().empty()) << oss.str();
     oss.str("");
     rc = butil::read_command_output(oss, "kill -9 $$");
     ASSERT_EQ(-1, rc);
@@ -36,8 +35,8 @@ TEST(PopenTest, sanity) {
     ASSERT_TRUE(butil::StringPiece(oss.str()).ends_with("was killed by signal 15"));
 
     oss.str("");
-    ASSERT_EQ(0, butil::read_command_output(oss, "printf '=%.0s' {1..100000}"));
-    ASSERT_EQ(100000u, oss.str().length());
+    ASSERT_EQ(0, butil::read_command_output(oss, "for i in `seq 1 100000`; do echo -n '=' ; done"));
+    ASSERT_EQ(100000u, oss.str().length()) << oss.str();
     std::string expected;
     expected.resize(100000, '=');
     ASSERT_EQ(expected, oss.str());