INFO: setup
Package:    sys-boot/os-prober-1.81-r2:0
Repository: gentoo
Maintainer: plevine457@gmail.com bkohler@gentoo.org
USE:        abi_x86_64 amd64 elibc_glibc kernel_linux
FEATURES:   preserve-libs sandbox userpriv usersandbox
INFO: prepare
Applying os-prober-1.79-mdraid-detection.patch ...
Applying os-prober-1.79-btrfs-subvolume-detection.patch ...
Applying os-prober-1.79-use-fstab-name.patch ...
Applying os-prober-1.79-mounted-boot-partition-fix.patch ...
Applying os-prober-1.79-fix-busy-umount-message.patch ...
Applying os-prober-1.79-efi-chroot-blkid-fallback.patch ...
Applying os-prober-1.81-boot-detected-twice-v2.patch ...
INFO: install
Final size of build directory: 260 KiB
Final size of installed tree:  184 KiB
LOG: postinst
If you intend for os-prober to detect versions of Windows installed
on NTFS-formatted partitions, your system must be capable of reading
the NTFS filesystem. One way to do this is by installing
sys-fs/ntfs3g. NOTE: Since sys-boot/grub-2.06-rc1, grub-mkconfig
disables os-prober by default. To enable it, add
GRUB_DISABLE_OS_PROBER=false to /etc/default/grub.

(Note: Above message is only printed the first time package is
installed. Please look at /usr/share/doc/os-prober-1.81-r2/README.gentoo*
for future reference)