have we looked into why `strip` is failing and what it'd take to fix the problem ?  i'm not sure trying to switch the entire system over to eu-strip is a less risky proposition ... i vaguely recall having tried this in the past and it came with its own set of issues.

I tried to debug it last Friday but have not ping point the real problem.

From https://bugs.chromium.org/p/chromium/issues/detail?id=742655#c4, Android has made this switch.

Currently we only want to use eu-strip for chrome linked with lld. We may switch to llvm-strip in the future if it is ready.

if we're only changing the chrome ebuild to use eu-strip, that'd be fine from a reliability aspect, especially since it's the only thing currently using lld

are there plans to change CrOS in general to use lld by default ?  i.e. is there an open bug we can make this a blocker of so we don't forget ?

Currently we do not have plan to use lld by default.
This is a bug entry about using lld to link chrome for linux
in  crbug.com/607968  and it seems the migration for linux is completed.

migrating to LLD for everything is a long term goal. 
So, yes, we should file a bug with P=3. 
For now, we only care about Chrome. 

Just filed a bug and used our new component for bugs in crbug.com/809268

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/3fc71d6766e169da97ec345059e273aca8d94af8

commit 3fc71d6766e169da97ec345059e273aca8d94af8
Author: Yunlian Jiang <yunlian@chromium.org>
Date: Wed Feb 07 02:18:57 2018

re-enable USE=utils for elfutils on host

This reverts commit ee1c59430d09cc7d98475ab411800d94928f8edb.

Reason for revert: We want to use eu-strip because strip from binutils
has a bug to strip binaries linked with lld.  crbug.com/808262 

Original change's description:
> profile: set USE=-utils for elfutils on host.
>
> We want to get rid of elfutils because it cannot be built with
> clang. Removing the utils provided by it is the first step.
>
> BUG=chromium:217722
> TEST=cbuildbot chromiumos-sdk
>
> Change-Id: I18e126fe0ab82dc77509c107d700ef185b79f49d
> Reviewed-on: https://chromium-review.googlesource.com/609403
> Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
> Tested-by: Yunlian Jiang <yunlian@chromium.org>
> Reviewed-by: Mike Frysinger <vapier@chromium.org>

BUG= chromium:808262 
TEST=sudo emerge elfutils
     eu-strip works on binaries linked with lld.
Change-Id: I0d3c9b1c45283c0ecaec25018ec3f43745c7341e
Reviewed-on: https://chromium-review.googlesource.com/901923
Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
Tested-by: Yunlian Jiang <yunlian@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/3fc71d6766e169da97ec345059e273aca8d94af8/profiles/targets/sdk/package.use

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/dfe6945d9426165a53a45534341f35391af6e652

commit dfe6945d9426165a53a45534341f35391af6e652
Author: Yunlian Jiang <yunlian@chromium.org>
Date: Fri Mar 09 01:01:09 2018

chromeos-chrome: use eu-strip when USE="lld" is set.

'strip' from binutils has a bug and it messed up the elf
program header when a binary is linked with LLD. As a workaround,
use eu-strip instead.

BUG= chromium:808262 
TEST=USE="-gold lld" emerge-samus chromeos-chrome

Change-Id: Ie8a7c6ca0198716ba9e69be58dde4478c63f66d9
Reviewed-on: https://chromium-review.googlesource.com/956009
Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
Tested-by: Yunlian Jiang <yunlian@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>

[modify] https://crrev.com/dfe6945d9426165a53a45534341f35391af6e652/chromeos-base/chromeos-chrome/chromeos-chrome-9999.ebuild

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/2cb91dc6dfcb35c330f909c8be2f7d46333362ac

commit 2cb91dc6dfcb35c330f909c8be2f7d46333362ac
Author: Yunlian Jiang <yunlian@chromium.org>
Date: Sat Mar 10 01:39:25 2018

cros_setup_toolchain: add elfutils to sdk.

We want to use eu-strip to strip chrome binary, so we need to
add elfutils to chrome_sdk to make simple chrome work.

BUG= chromium:808262 
TEST=cbuildbot chromiumos-sdk

Change-Id: I66f36fd057861ba56199d6bbb39d9566b978be69
Reviewed-on: https://chromium-review.googlesource.com/955887
Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
Tested-by: Yunlian Jiang <yunlian@chromium.org>
Reviewed-by: Caroline Tice <cmtice@chromium.org>

[modify] https://crrev.com/2cb91dc6dfcb35c330f909c8be2f7d46333362ac/scripts/cros_setup_toolchains.py

can this be closed now? 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/bcbd65eae99e526d842b6629146b3d9f35d7d497

commit bcbd65eae99e526d842b6629146b3d9f35d7d497
Author: Yunlian Jiang <yunlian@google.com>
Date: Sun Sep 02 01:33:46 2018

chromeos-chrome: use 'strip' instead of 'eu-strip' with LLD.

Previously we changed to use eu-strip when using LLD to link chrome.
This is because using 'strip' corrupts the GNU_RELRO part of program
header.
However, using eu-strip makes the dump_syms crash and we could not
get the valid breakpad symbol files. Using 'strip' from binutils works
fine in this case. I verified that the error reported in the bug was
gone, probably it is becaues we upgraded LLD after the bug was reported.
We also remove the link flag -Wl,--no-rosegment because we added that in
the LLD wrapper already.

BUG= chromium:808262 
TEST=USE="-gold lld" emerge-samus chromeos-chrome
     checked the output of
     readelf -l on stripped chrome binary, the GNU_RELRO part is
     still there.
     cros_generate_breakpad_symbols --board samus
      /build/samus/opt/google/chrome/chrome
     it generates valid symbol files.

Change-Id: I54f604d5e3b3be2a92335c8f8a83931ff997f465
Reviewed-on: https://chromium-review.googlesource.com/1200323
Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
Tested-by: Yunlian Jiang <yunlian@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>

[modify] https://crrev.com/bcbd65eae99e526d842b6629146b3d9f35d7d497/chromeos-base/chromeos-chrome/chromeos-chrome-9999.ebuild