Encountering issues while building Linux From Scratch (LFS) on a Debian environment within Windows Subsystem for Linux (WSL) can be frustrating, especially when core utilities go missing inside the chroot environment. A common problem that halts progress is the LFS chroot failing to locate essential binaries like /usr/bin/env.

This specific error, “LFS chroot cannot find /usr/bin/env,” typically points to an incorrectly configured or incomplete limited directory layout within the LFS filesystem. As outlined in chapter 4.2, “Creating a Limited Directory Layout in the LFS Filesystem,” of the official LFS book (e.g., LFS-BOOK-12.4), several crucial symbolic links must be established.

The problem often arises when the command ln -sv usr/$i $LFS/$i is not executed successfully or is overlooked for critical directories like lib, bin, and sbin. The absence of these symbolic links means that /lib does not point to /usr/lib, /bin does not point to /usr/bin, and /sbin does not point to /usr/sbin within the new LFS filesystem. When the chroot environment is entered, the system expects these standard paths to be present, and without them, commands like env (which resides in /usr/bin) become unreachable.

To resolve this issue, ensure the correct symbolic links are created within your LFS system. Specifically, you will need to manually create the missing symlinks by executing commands similar to these, assuming $LFS is correctly set to your LFS mount point:

ln -sv usr/lib $LFS/lib
ln -sv usr/bin $LFS/bin
ln -sv usr/sbin $LFS/sbin

Running these commands will establish the necessary pointers from the root of your LFS system to the corresponding directories under /usr, thereby rectifying the filesystem layout and allowing the chroot environment to find /usr/bin/env and other vital utilities, enabling you to proceed with your Linux From Scratch build.