emerge -uDNv world

These are the packages that would be merged, in order:

Calculating world dependencies... done!

Total: 0 packages, Size of downloads: 0 kB

>>> Auto-cleaning packages...

 app-arch/unzip
    selected: 5.52-r1
   protected: 5.52-r2
     omitted: none

>>> 'Selected' packages are slated for removal.
>>> 'Protected' and 'omitted' packages will not be removed.

>>> Unmerging app-arch/unzip-5.52-r1...
/var/tmp/binpkgs/app-arch/unzip-5.52-r1/temp/environment: line 254: syntax error near unexpected token `('
/var/tmp/binpkgs/app-arch/unzip-5.52-r1/temp/environment: line 254: `            done <<(get_mounts);'
 *
 * ERROR: app-arch/unzip-5.52-r1 failed.
 * Call stack:
 *               ebuild.sh, line 1641:  Called die
 * The specific snippet of code:
 *      preprocess_ebuild_env || \
 *              die "error processing environment"
 *  The die message:
 *   error processing environment
 *
 * If you need support, post the topmost build error, and the call stack if relevant.
 * A complete build log is located at '/var/log/portage/app-arch:unzip-5.52-r1:20080329-123442.log'.
 * The ebuild environment file is located at '/var/tmp/binpkgs/app-arch/unzip-5.52-r1/temp/environment'.
 *
!!! FAILED prerm: 1
 * The 'prerm' phase of the 'app-arch/unzip-5.52-r1' package has failed
 * with exit value 1. The problem occurred while executing the ebuild
 * located at '/var/db/pkg/app-arch/unzip-5.52-r1/unzip-5.52-r1.ebuild'. If
 * necessary, manually remove the ebuild in order to skip the execution of
 * removal phases.

 * Messages for package app-arch/unzip-5.52-r1:

 *
 * ERROR: app-arch/unzip-5.52-r1 failed.
 * Call stack:
 *               ebuild.sh, line 1641:  Called die
 * The specific snippet of code:
 *      preprocess_ebuild_env || \
 *              die "error processing environment"
 *  The die message:
 *   error processing environment
 *
 * If you need support, post the topmost build error, and the call stack if relevant.
 * A complete build log is located at '/var/log/portage/app-arch:unzip-5.52-r1:20080329-123442.log'.
 * The ebuild environment file is located at '/var/tmp/binpkgs/app-arch/unzip-5.52-r1/temp/environment'.
 *
 * The 'prerm' phase of the 'app-arch/unzip-5.52-r1' package has failed
 * with exit value 1. The problem occurred while executing the ebuild
 * located at '/var/db/pkg/app-arch/unzip-5.52-r1/unzip-5.52-r1.ebuild'. If
 * necessary, manually remove the ebuild in order to skip the execution of
 * removal phases.