Update azure-pipelines.yml

azure-pipelines.yml

@@ -188,13 +188,15 @@ jobs:
   steps:   
   - script: |
       brew update
-      brew install llvm stow
+      brew install llvm stow libpthread libpthread-stubs
       sudo mkdir /usr/local/stow
       sudo wget -P /usr/local/stow https://github.com/meow464/flang/releases/download/flang_20210324/flang.tar
       cd /usr/local/stow
       sudo tar xf flang.tar
       sudo stow flang
       cd -
+      which flang
+      whence flang
       make  CC=/usr/local/opt/llvm/bin/clang FC=flang
       
 - job: OSX_Ifort_Clang