package cuda: fix for chmod error (#17596)

* fix if cached cuda  is only rx

* use shell to install; rm chmod commands

* flake8 fix

* flake8 fix

Co-authored-by: lu64bag3 <gerald.mathias@lrz.de>

var/spack/repos/builtin/packages/cuda/package.py

@@ -97,7 +97,7 @@ def determine_version(cls, exe):
 
     def setup_build_environment(self, env):
         if self.spec.satisfies('@10.1.243:'):
-            libxml2_home  = self.spec['libxml2'].prefix
+            libxml2_home = self.spec['libxml2'].prefix
             env.set('LIBXML2HOME', libxml2_home)
             env.append_path('LD_LIBRARY_PATH', libxml2_home.lib)
 
@@ -117,9 +117,6 @@ def install(self, spec, prefix):
                             "presence of /tmp/cuda-installer.log "
                             "please remove the file and try again ")
         runfile = glob(join_path(self.stage.source_path, 'cuda*_linux*'))[0]
-        chmod = which('chmod')
-        chmod('+x', runfile)
-        runfile = which(runfile)
 
         # Note: NVIDIA does not officially support many newer versions of
         # compilers.  For example, on CentOS 6, you must use GCC 4.4.7 or
@@ -130,6 +127,7 @@ def install(self, spec, prefix):
 
         # CUDA 10.1+ has different cmdline options for the installer
         arguments = [
+            runfile,            # the install script
             '--silent',         # disable interactive prompts
             '--override',       # override compiler version checks
             '--toolkit',        # install CUDA Toolkit
@@ -139,8 +137,8 @@ def install(self, spec, prefix):
         else:
             arguments.append('--verbose')                   # Verbose log file
             arguments.append('--toolkitpath=%s' % prefix)   # Where to install
-
-        runfile(*arguments)
+        install_shell = which('sh')
+        install_shell(*arguments)
         try:
             os.remove('/tmp/cuda-installer.log')
         except OSError: