/tmp/packages # PKGDIR="/tmp/packages" emerge --oneshot sys-libs/ncurses-6.1_p20181020.tbz2

*** emerging by path is broken and may not always work!!!

Calculating dependencies... done!

>>> Emerging binary (1 of 1) sys-libs/ncurses-6.1_p20181020::gentoo
 * ncurses-6.1_p20181020.tbz2 size ;-) ...                               [ ok ]
>>> Extracting info
>>> Extracting sys-libs/ncurses-6.1_p20181020

>>> Installing (1 of 1) sys-libs/ncurses-6.1_p20181020::gentoo
Traceback (most recent call last):
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/_MergeProcess.py", line 234, in _spawn
    prev_mtimes=self.prev_mtimes, counter=counter)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 1679, in wrapper
    return f(self, *args, **kwargs)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 5226, in merge
    counter=counter)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 4470, in treewalk
    preserve_paths=preserve_paths)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 1679, in wrapper
    return f(self, *args, **kwargs)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 2101, in unmerge
    preserve_paths=preserve_paths)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 1941, in _prune_plib_registry
    unmerge_no_replacement)
  File "/usr/lib64/python3.6/site-packages/portage/dbapi/vartree.py", line 3300, in _find_unused_preserved_libs
    for c in self.vartree.dbapi._linkmap.findConsumers(f):
  File "/usr/lib64/python3.6/site-packages/portage/util/_dyn_libs/LinkageMapELF.py", line 799, in findConsumers
    raise KeyError("%s (%s) not in object list" % (obj_key, obj))
KeyError: '<portage.util._dyn_libs.LinkageMapELF.LinkageMapELF._ObjectKey object at 0x7f3bf475ea08> (/usr/lib/libncurses.so.6.1) not in object list'

>>> Failed to install sys-libs/ncurses-6.1_p20181020, Log file:

>>>  '/var/tmp/portage/sys-libs/ncurses-6.1_p20181020/temp/build.log'

 * GNU info directory index is up-to-date.

!!! existing preserved libs:
>>> package: sys-libs/ncurses-6.1_p20181020
 *  - /usr/lib/libncurses.so.6
 *  - /usr/lib/libncurses.so.6.1
 *      used by /usr/lib/libgpm.so.1.20.0 (sys-libs/gpm-1.20.7-r2)
 *  - /usr/lib/libtinfo.so.6
 *  - /usr/lib/libtinfo.so.6.1
 *      used by /lib/security/pam_cap.so (sys-libs/libcap-2.26-r2)
 *      used by /usr/lib/engines-1.1/afalg.so (dev-libs/openssl-1.1.1d-r2)
 *      used by /usr/lib/engines-1.1/capi.so (dev-libs/openssl-1.1.1d-r2)
 *      used by 147 other files
Use emerge @preserved-rebuild to rebuild packages using these libraries