Host : Ubuntu 14.04
Problem is seen with Cheza chroot environment.
Public tree init/sync today (4.Dec.2018) with local/private manifest from:
https://partnerissuetracker.corp.google.com/issues/77967911

Below is screen capture from trying to build bmpblk with only en fonts to save space in firmware image.

(cr) ((639a155...)) mturney@mturney-linux ~/trunk/src/scripts $ export BOARD=cheza
(cr) ((639a155...)) mturney@mturney-linux ~/trunk/src/scripts $ LOCALES=en emerge-${BOARD} chromeos-bmpblk
!!! CONFIG_PROTECT is empty for '/build/cheza/'
Calculating dependencies... done!

>>> Emerging (1 of 1) sys-boot/chromeos-bmpblk-1.0.1-r71::chromiumos for /build/cheza/
 * Running stacked hooks for pre_pkg_setup
 *    sysroot_build_bin_dir ...                                                                                                                                             [ ok ]
 * Running stacked hooks for post_pkg_setup
 *    python_eclass_hack ...                                                                                                                                                [ ok ]
 * Running stacked hooks for pre_src_unpack
 *    python_multilib_setup ...                                                                                                                                             [ ok ]
>>> Unpacking source...
 * Using local source dir(s): /mnt/host/source/src/third_party/../platform/bmpblk
 * path: /mnt/host/source/src/third_party/../platform/bmpblk
 * destdir: /build/cheza/tmp/portage/sys-boot/chromeos-bmpblk-1.0.1-r71/work/chromeos-bmpblk-1.0.1
>>> Source unpacked in /build/cheza/tmp/portage/sys-boot/chromeos-bmpblk-1.0.1-r71/work
 * Running stacked hooks for post_src_unpack
 *    asan_init ...                                                                                                                                                         [ ok ]
>>> Preparing source in /mnt/host/source/src/platform/bmpblk ...
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/croscore/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/crosextra/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/dejavu/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/ko-nanum/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/lohit-cros/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/noto/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/notocjk/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/roboto/.uuid.TMP-XXXXXX
 * ACCESS DENIED:  mkostemp:     /usr/share/fonts/tibt-jomolhari/.uuid.TMP-XXXXXX
/usr/share/fonts/croscore: skipping, existing cache is valid: 12 fonts, 0 dirs
/usr/share/fonts/crosextra: skipping, existing cache is valid: 8 fonts, 0 dirs
/usr/share/fonts/dejavu: skipping, existing cache is valid: 21 fonts, 0 dirs
/usr/share/fonts/ko-nanum: skipping, existing cache is valid: 2 fonts, 0 dirs
/usr/share/fonts/lohit-cros: skipping, existing cache is valid: 2 fonts, 0 dirs
/usr/share/fonts/monotype: skipping, no such directory
/usr/share/fonts/noto: skipping, existing cache is valid: 195 fonts, 0 dirs
/usr/share/fonts/notocjk: skipping, existing cache is valid: 32 fonts, 0 dirs
/usr/share/fonts/roboto: skipping, existing cache is valid: 12 fonts, 0 dirs
/usr/share/fonts/tibt-jomolhari: skipping, existing cache is valid: 1 fonts, 0 dirs
/usr/share/fonts/google-sans: skipping, no such directory
/build/cheza/tmp/portage/sys-boot/chromeos-bmpblk-1.0.1-r71/temp/tmp.pY9I2Pndvg: cleaning cache directory
/usr/share/cache/fontconfig: not cleaning unwritable cache directory
fc-cache: succeeded
>>> Source prepared.
 * --------------------------- ACCESS VIOLATION SUMMARY ---------------------------
 * LOG FILE: "/var/log/sandbox/sandbox-10937.log"
 * 
VERSION 1.0
FORMAT: F - Function called
FORMAT: S - Access Status
FORMAT: P - Path as passed to function
FORMAT: A - Absolute Path (not canonical)
FORMAT: R - Canonical Path
FORMAT: C - Command Line

F: mkostemp
S: deny
P: /usr/share/fonts/croscore/.uuid.TMP-XXXXXX
A: /usr/share/fonts/croscore/.uuid.TMP-XXXXXX
R: /usr/share/fonts/croscore/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/crosextra/.uuid.TMP-XXXXXX
A: /usr/share/fonts/crosextra/.uuid.TMP-XXXXXX
R: /usr/share/fonts/crosextra/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/dejavu/.uuid.TMP-XXXXXX
A: /usr/share/fonts/dejavu/.uuid.TMP-XXXXXX
R: /usr/share/fonts/dejavu/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/ko-nanum/.uuid.TMP-XXXXXX
A: /usr/share/fonts/ko-nanum/.uuid.TMP-XXXXXX
R: /usr/share/fonts/ko-nanum/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/lohit-cros/.uuid.TMP-XXXXXX
A: /usr/share/fonts/lohit-cros/.uuid.TMP-XXXXXX
R: /usr/share/fonts/lohit-cros/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/noto/.uuid.TMP-XXXXXX
A: /usr/share/fonts/noto/.uuid.TMP-XXXXXX
R: /usr/share/fonts/noto/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/notocjk/.uuid.TMP-XXXXXX
A: /usr/share/fonts/notocjk/.uuid.TMP-XXXXXX
R: /usr/share/fonts/notocjk/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/roboto/.uuid.TMP-XXXXXX
A: /usr/share/fonts/roboto/.uuid.TMP-XXXXXX
R: /usr/share/fonts/roboto/.uuid.TMP-XXXXXX
C: fc-cache -v 

F: mkostemp
S: deny
P: /usr/share/fonts/tibt-jomolhari/.uuid.TMP-XXXXXX
A: /usr/share/fonts/tibt-jomolhari/.uuid.TMP-XXXXXX
R: /usr/share/fonts/tibt-jomolhari/.uuid.TMP-XXXXXX
C: fc-cache -v 
 * --------------------------------------------------------------------------------

>>> Failed to emerge sys-boot/chromeos-bmpblk-1.0.1-r71 for /build/cheza/, Log file:

>>>  '/build/cheza/tmp/portage/logs/sys-boot:chromeos-bmpblk-1.0.1-r71:20181204-170012.log'
(cr) ((639a155...)) mturney@mturney-linux ~/trunk/src/scripts $ fc-cache --really-force --sysroot=/build/cheza
(cr) ((639a155...)) mturney@mturney-linux ~/trunk/src/scripts $