https://uberchromegw.corp.google.com/i/chromeos/builders/rambi-release/builds/753

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** Finished Stage BuildPackages [afdo_use] - Thu, 21 Apr 2016 00:51:00 +0000 (UTC)
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Still building adhd-0.0.1-r1268 (33m40.6s). Logs in /tmp/adhd-0.0.1-r1268-M1zyp9
Still building dfu-programmer-0.7.2 (33m40.6s). Logs in /tmp/dfu-programmer-0.7.2-jY53Gr
Still building openssh-6.6.1_p1-r2 (92m45.2s). Logs in /tmp/openssh-6.6.1_p1-r2-aaEnkW
Still building usbutils-007-r1 (9m13.9s). Logs in /tmp/usbutils-007-r1-GA9VET
Still building python-uinput-0.10.2-r1 (33m40.6s). Logs in /tmp/python-uinput-0.10.2-r1-ygwZb0
Still building dhcpcd-6.8.2-r17 (33m40.6s). Logs in /tmp/dhcpcd-6.8.2-r17-gowLxZ
Still building libscrypt-1.1.6-r12 (68m35.8s). Logs in /tmp/libscrypt-1.1.6-r12-ks01rf
Still building gcc-libs-4.9.2-r32 (68m35.8s). Logs in /tmp/gcc-libs-4.9.2-r32-QbnJSS
Still building chromeos-kernel-3_10-3.10.18-r820 (49m50.3s). Logs in /tmp/chromeos-kernel-3_10-3.10.18-r820-OFuSvj
Still building lshw-02.17b-r1 (9m13.9s). Logs in /tmp/lshw-02.17b-r1-43iAos
Still building pytest-2.3.5 (25m57.7s). Logs in /tmp/pytest-2.3.5-a0qDU6
Still building tlsdate-0.0.5-r42 (68m35.8s). Logs in /tmp/tlsdate-0.0.5-r42-D0Hguk
Still building chromite-0.0.2-r2344 (68m35.8s). Logs in /tmp/chromite-0.0.2-r2344-KGqsuC
Still building glib-2.34.3-r4 (123m18.9s). Logs in /tmp/glib-2.34.3-r4-WKiMLP
Still building chromeos-auth-config-1-r0 (9m14.1s). Logs in /tmp/chromeos-auth-config-1-r0-xH8IU7
Still building binutils-2.25.51-r57 (68m35.8s). Logs in /tmp/binutils-2.25.51-r57-nbntY7
Still building autotest-deps-ltp-0.20150119-r12 (68m35.8s). Logs in /tmp/autotest-deps-ltp-0.20150119-r12-j7m6Ij
Still building google-apputils-0.4.0 (27m59.1s). Logs in /tmp/google-apputils-0.4.0-Vr9jiA
Still building google-breakpad-2016.03.10.135120-r97 (68m35.8s). Logs in /tmp/google-breakpad-2016.03.10.135120-r97-pHgZT7
Still building pciutils-3.1.10 (9m13.9s). Logs in /tmp/pciutils-3.1.10-gYbwz9
Still building libmtp-0.0.1-r21 (68m35.8s). Logs in /tmp/libmtp-0.0.1-r21-ECCxtu
Still building libdrm-2.4.66-r9 (33m40.6s). Logs in /tmp/libdrm-2.4.66-r9-A12HBm
Still building e2fsprogs-1.42.12 (101m19.0s). Logs in /tmp/e2fsprogs-1.42.12-wCTMgK
Still building chromeos-ec-0.0.1-r2971 (68m35.8s). Logs in /tmp/chromeos-ec-0.0.1-r2971-sNtY8b
Still building autotest-0.0.2-r7197 (68m35.8s). Logs in /tmp/autotest-0.0.2-r7197-d4WVzs
Still building chromeos-assets-0.0.2-r128 (68m35.8s). Logs in /tmp/chromeos-assets-0.0.2-r128-Ah0rJJ
Still building libpayload-0.0.1-r2357 (68m35.8s). Logs in /tmp/libpayload-0.0.1-r2357-k_i_dT
cros_sdk: Signaled to shutdown: caught 15 signal.
Timeout occurred- waited 28010 seconds, failing. Timeout reason: Slave reached the timeout deadline set by master.

I do not see anything obvious in the log, just packages build hanging for no apparent reason.

https://uberchromegw.corp.google.com/i/chromeos/builders/rambi-release/builds/754 seems to be having the same issue currently.