I got following error after update Arch Linux kernel to 4.11.2-1.

sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the ‘nosuid’ option set or an NFS file system without root privileges?

How to fix this error:

  1. Clone the linux kernel package.

    git clone https://git.archlinux.org/svntogit/packages.git --single-branch -b packages/linux kernel

  2. Download the patch file and save to “kernel” directory.

    linux-ptrace-fix.patch

  3. The “kernel” directory looks like this.

    kernel/linux-ptrace-fix.patch
kernel/trunk/90-linux.hook
kernel/trunk/PKGBUILD
kernel/trunk/config.i686
kernel/trunk/config.x86_64
kernel/trunk/linux.install
kernel/trunk/linux.preset

  4. Apply the patch.

    cd kernel
patch -p1 -i linux-ptrace-fix.patch

  5. Install xmlto package.

    sudo pacman -S xmlto

  6. Import GPG keys of Linus Torvalds and Greg Kroah-Hartman.

    gpg2 --keyserver hkp://keys.gnupg.net --recv-keys 79BE3E4300411886
gpg2 --keyserver hkp://keys.gnupg.net --recv-keys 38DBBDC86092693E

  7. Build packages. (this will take long time.)

    cd trunk
makepkg

  8. Install the packages.

    sudo pacman -U linux-4.11.2-1-x86_64.pkg.tar.xz
sudo pacman -U linux-headers-4.11.2-1-x86_64.pkg.tar.xz
sudo pacman -U linux-docs-4.11.2-1-x86_64.pkg.tar.xz

  9. Reboot the system.

Notes:

  • This sudo error was reported in below page.

    Kernel 4.11.2 does not let user run su or sudo under Enlightenment

  • You will get following error if the GPG keys are not imported. (above step 6)

      ==> Verifying source file signatures with gpg...
      linux-4.11.tar ... FAILED (unknown public key 79BE3E4300411886)
      patch-4.11.2 ... FAILED (unknown public key 38DBBDC86092693E)
  ==> ERROR: One or more PGP signatures could not be verified!

  • An alternative way to avoid the sudo error is using Linux LTS (Long Term Support) kernel.

    Install the linux-lts package