Happening in the PFQ and locally:

=== Start output for job boost-1.62.0-r1 (0m2.0s) ===
boost-1.62.0-r1: >>> Emerging (1 of 1) dev-libs/boost-1.62.0-r1::portage-stable for /build/arm-generic/
boost-1.62.0-r1:   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
boost-1.62.0-r1:                                  Dload  Upload   Total   Spent    Left  Speed
boost-1.62.0-r1: 
boost-1.62.0-r1:   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
boost-1.62.0-r1:   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
boost-1.62.0-r1: curl: (22) The requested URL returned error: 404 Not Found
boost-1.62.0-r1:   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
boost-1.62.0-r1:                                  Dload  Upload   Total   Spent    Left  Speed
boost-1.62.0-r1: 
boost-1.62.0-r1:   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
boost-1.62.0-r1:   4 80.5M    4 4096k    0     0  11.1M      0  0:00:07 --:--:--  0:00:07 11.2M
boost-1.62.0-r1: 100 80.5M  100 80.5M    0     0  76.8M      0  0:00:01  0:00:01 --:--:-- 76.9M
boost-1.62.0-r1: !!! Fetched file: boost_1_62_0.tar.bz2 VERIFY FAILED!
boost-1.62.0-r1: !!! Reason: Filesize does not match recorded size
boost-1.62.0-r1: !!! Got:      84513338
boost-1.62.0-r1: !!! Expected: 84529021
boost-1.62.0-r1: Refetching... File renamed to '/var/cache/chromeos-cache/distfiles/target/boost_1_62_0.tar.bz2._checksum_failure_.X45Iro'
boost-1.62.0-r1: 
boost-1.62.0-r1: !!! Couldn't download 'boost_1_62_0.tar.bz2'. Aborting.
boost-1.62.0-r1:  * Fetch failed for 'dev-libs/boost-1.62.0-r1', Log file:
boost-1.62.0-r1:  *  '/build/arm-generic/tmp/portage/logs/dev-libs:boost-1.62.0-r1:20170419-173711.log'
boost-1.62.0-r1: >>> Failed to emerge dev-libs/boost-1.62.0-r1 for /build/arm-generic/, Log file:
boost-1.62.0-r1: >>>  '/build/arm-generic/tmp/portage/logs/dev-libs:boost-1.62.0-r1:20170419-173711.log'
boost-1.62.0-r1: 
boost-1.62.0-r1:  * Messages for package dev-libs/boost-1.62.0-r1 merged to /build/arm-generic/:
boost-1.62.0-r1: 
boost-1.62.0-r1:  * Fetch failed for 'dev-libs/boost-1.62.0-r1', Log file:
boost-1.62.0-r1:  *  '/build/arm-generic/tmp/portage/logs/dev-libs:boost-1.62.0-r1:20170419-173711.log'
=== Complete: job boost-1.62.0-r1 (0m2.0s) ===
Failed dev-libs/boost-1.62.0-r1 (in 0m2.0s). Your build has failed.
Pending 4/617, [Time 10:37:13 | Elapsed 57m6.6s | Load 1.84 4.29 15.87]
Packages failed:
	dev-libs/boost-1.62.0-r1
ERROR   : Wed Apr 19 10:37:13 PDT 2017
ERROR   :   PGID   PPID    PID     ELAPSED     TIME %CPU COMMAND
ERROR   :     10      6     10    01:05:27 00:00:00  0.0 -bash
ERROR   :  26744     10  26744       59:13 00:00:00  0.0  \_ /bin/bash ./build_packages --board=arm-generic
ERROR   :  26744  26744  14108       00:00 00:00:00  0.0      \_ /bin/bash ./build_packages --board=arm-generic
ERROR   :  26744  14108  14109       00:00 00:00:00  0.0          \_ ps f -o pgid,ppid,pid,etime,cputime,%cpu,command
ERROR   : Arguments of 26744: ./build_packages '--board=arm-generic'
ERROR   : Backtrace:  (most recent call is last)
ERROR   :  build_packages:307:main(), called: die_err_trap  
ERROR   : 
ERROR   : Command failed:
ERROR   :   Command '( if [[ "${FLAGS_run_goma}" -eq "${FLAGS_TRUE}" ]]; then
ERROR   :     info "Starting goma compiler_proxy."; goma_ctl="${GOMA_DIR:-${HOME}/goma}/goma_ctl.py"; "${goma_ctl}" restart; trap "\"${goma_ctl}\" stop" EXIT;
ERROR   : fi; set -o pipefail; sudo -E "${EMERGE_CMD[@]}" "${EMERGE_FLAGS[@]}" "${PACKAGES[@]}" | tee "${tmpfile}" )' exited with nonzero code: 1