diff --git a/gitlab/functions.sh b/gitlab/functions.sh
index 7882db0fbea9c8b190cf29b96d76c0abfa4346e4..bbcd47c515b3d80f6c16cc382ad23d1c995497fa 100644
--- a/gitlab/functions.sh
+++ b/gitlab/functions.sh
@@ -3,8 +3,8 @@
 
 # Build utilities
 
-# Determines the architecture we're using
-arch() {
+# Determines the operating system we're using
+osname() {
   [[ "$(uname -s)" == "Darwin" ]] && echo "macosx" || echo "linux"
 }
 
@@ -196,7 +196,7 @@ check_pass DOCUSER
 check_pass DOCPASS
 
 # Sets up variables
-ARCH=`arch`
+OSNAME=`osname`
 
 if [ -z "${CONDA_FOLDER}" ]; then
   CONDA_FOLDER=/opt/conda
@@ -213,15 +213,28 @@ fi
 
 PREFIX=${CI_PROJECT_DIR}/${VIRTUALENV_PATH}
 
-if [ "${ARCH}" == "linux" ]; then
+if [ "${OSNAME}" == "linux" ]; then
   # Temporary hack to get building done right with gcc-5 compilers
   if [ -z "${CFLAGS}" ]; then
-    CFLAGS="-D_GLIBCXX_USE_CXX11_ABI=0"
+    CFLAGS="-D_GLIBCXX_USE_CXX11_ABI=0 -pthread"
   else
-    CFLAGS="${CFLAGS} -D_GLIBCXX_USE_CXX11_ABI=0"
+      if [[ "${CFLAGS}" != *-pthread* ]]; then
+        CFLAGS="${CFLAGS} -pthread"
+      fi
+      if [[ "${CFLAGS}" != *-D_GLIBCXX_USE_CXX11_ABI=0* ]]; then
+        CFLAGS="${CFLAGS} -D_GLIBCXX_USE_CXX11_ABI=0"
+      fi
+  fi
+else #macosx
+  if [ -z "${CFLAGS}" ]; then
+    CFLAGS="-pthread"
+  elif [[ "${CFLAGS}" != *-pthread* ]]; then
+        CFLAGS="${CFLAGS} -pthread"
+  fi
+  if [ "${CFLAGS}" == *-DBZ_DEBUG* ]; then
+    # -DBZ_DEBUG does not work well with clang
+    CFLAGS=`echo ${CFLAGS} | sed -e s/\s*-DBZ_DEBUG//g`
   fi
-else
-  CFLAGS=""
 fi
 CXXFLAGS=${CFLAGS}
 
@@ -236,8 +249,9 @@ if [ -z "${BOB_PREFIX_PATH}" ]; then
   fi
 fi
 LD_LIBRARY_PATH=${BOB_PREFIX_PATH}/lib
-if [ "${ARCH}" == "macosx" ]; then
+if [ "${OSNAME}" == "macosx" ]; then
   DYLD_FALLBACK_LIBRARY_PATH=${BOB_PREFIX_PATH}/lib
+  MACOSX_DEPLOYMENT_TARGET=10.9
 fi
 
 if [ -z "${PYPISERVER}" ]; then
@@ -246,7 +260,7 @@ fi
 
 TESTSERVER=https://testpypi.python.org/pypi
 
-check_env ARCH
+check_env OSNAME
 check_env PYVER
 check_env PREFIX
 export_env CFLAGS
@@ -257,8 +271,9 @@ check_env TESTSERVER
 check_env CONDA_FOLDER
 check_env VIRTUALENV_PATH
 export_env LD_LIBRARY_PATH
-if [ "${ARCH}" == "macosx" ]; then
+if [ "${OSNAME}" == "macosx" ]; then
   export_env DYLD_FALLBACK_LIBRARY_PATH
+  export_env MACOSX_DEPLOYMENT_TARGET
 fi
 export_env BOB_PREFIX_PATH
 
@@ -277,10 +292,3 @@ fi
 
 # Activates conda environment
 run_cmd source ${BOB_PREFIX_PATH}/bin/activate `basename ${BOB_PREFIX_PATH}`
-
-# Patches conda environment
-log_info "Patching build flags to provide for conda..."
-CFLAGS="${CFLAGS} -pthread"
-export_env CFLAGS
-CXXFLAGS="${CXXFLAGS} -pthread"
-export_env CXXFLAGS