nvidia-installer log file '/var/log/nvidia-installer.log'
creation time: Fri Apr 23 09:24:04 2021
installer version: 334.21

PATH: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin

nvidia-installer command line:
    ./nvidia-installer

Unable to load: nvidia-installer ncurses user interface

Using built-in stream user interface
WARNING: You do not appear to have an NVIDIA GPU supported by the 334.21 NVIDIA Linux graphics driver installed in this system.  For further details, please see the appendix SUPPORTED NVIDIA GRAPHICS CHIPS in the README available on the Linux driver download page at www.nvidia.com.
-> License accepted.
-> Installing NVIDIA driver version 334.21.
-> An alternate method of installing the NVIDIA driver was detected. (This is usually a package provided by your distributor.) A driver installed via that method may integrate better with your system than a driver installed by nvidia-installer.

Please review the message provided by the maintainer of this alternate installation method and decide how to proceed:

The NVIDIA driver provided by Ubuntu can be installed by launching the "Software & Updates" application, and by selecting the NVIDIA driver from the "Additional Drivers" tab.


(Answer: Continue Installation)
-> Performing CC sanity check with CC="/usr/bin/cc".
-> Kernel source path: '/lib/modules/5.4.0-72-generic/build'
-> Kernel output path: '/lib/modules/5.4.0-72-generic/build'
-> Performing rivafb check.
-> Performing nvidiafb check.
-> Performing Xen check.
-> Performing PREEMPT_RT check.
-> Cleaning kernel module build directory.
   executing: 'cd ./kernel; /usr/bin/make clean'...
-> Building NVIDIA kernel module:
   executing: 'cd ./kernel; /usr/bin/make module SYSSRC=/lib/modules/5.4.0-72-generic/build SYSOUT=/lib/modules/5.4.0-72-generic/build NV_BUILD_MODULE_INSTANCES='...
   NVIDIA: calling KBUILD...
   make[1]: Entering directory '/usr/src/linux-headers-5.4.0-72-generic'
   /usr/bin/make -f ./Makefile syncconfig
   /usr/bin/make -f ./scripts/Makefile.build obj=scripts/basic
   rm -f .tmp_quiet_recordmcount
   /usr/bin/make -f ./scripts/Makefile.build obj=scripts/kconfig syncconfig
     flex -oscripts/kconfig/lexer.lex.c -L scripts/kconfig/lexer.l
   /bin/sh: 1: flex: not found
   make[3]: *** [scripts/Makefile.host:9: scripts/kconfig/lexer.lex.c] Error 127
   make[2]: *** [Makefile:617: syncconfig] Error 2
   make[1]: *** [Makefile:723: include/config/auto.conf.cmd] Error 2
   make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-72-generic'
   NVIDIA: left KBUILD.
    nvidia.ko failed to build!
   make: *** [Makefile:170: nvidia.ko] Error 1
-> Error.
ERROR: Unable to build the NVIDIA kernel module.
ERROR: Installation has failed.  Please see the file '/var/log/nvidia-installer.log' for details.  You may find suggestions on fixing installation problems in the README available on the Linux driver download page at www.nvidia.com.