Crashplan 4.6.0 upgrade failing (and solution)

Previously, I manually upgraded the JRE and glibc to get Crashplan 4.5.x running. Today I noticed it was stopped again, and checking my systems I saw that / was full due to multiple failed upgrade attempts by Crashplan (thanks for the graceful failure mode, Code42).

The log showed:

Sun Mar 27 19:54:03 EDT 2016 : Current Java Version: 1.8
Sun Mar 27 19:54:03 EDT 2016: The Current java is not compatible. Embedding a compatible version.
Sun Mar 27 19:54:03 EDT 2016 : Download JVM from http://download.code42.com/installs/proserver/jre/jre-7-linux-i586.tgz
Sun Mar 27 19:54:03 EDT 2016 : downloading the JRE using /usr/bin/wget

--2016-03-27 19:54:03-- http://download.code42.com/installs/proserver/jre/jre-7-linux-i586.tgz
Resolving download.code42.com... 216.17.8.19
Connecting to download.code42.com|216.17.8.19|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: https://download.code42.com/installs/proserver/jre/jre-7-linux-i586.tgz [following]
--2016-03-27 19:54:03-- https://download.code42.com/installs/proserver/jre/jre-7-linux-i586.tgz
Connecting to download.code42.com|216.17.8.19|:443... connected.
WARNING: certificate common name `store.code42.com' doesn't match requested host name `download.code42.com'.

This shows that the Crashplan update (to 4.6.0) was failing because:

1) It wanted to upgrade the JRE

2) It was trying to download the JRE with wget (it is nice of them to provide a JRE so we don't have to install one manually)

3) The address it was using was at "download.code42.com" but the certificate there was for "store.code42.com", so wget refused to do the download

Fortunately, this was pretty easy to fix. You can tell wget to ignore the certificate mismatch by creating a .wgetrc file in the $HOME directory, as mentioned here:

http://www.elftronix.com/how-to-automatically-skip-wget-ssl-certificate-check/

so use whatever editing method you prefer (I used vi) to create:

$HOME/.wgetrc

and insert:

check_certificate = off

Once I did that, the next upgrade attempt succeeded, and I am now running 4.6.0

Important: Don't forget to remove all of the failed upgrade directories from /usr/local/crashplan/upgrade so that you free up space on your root partition.