I'm running into this warning installing 1.7.1 via RPM. The RPM appears to have installed
$ ESVERSION=1.7.1
$ package=elasticsearch-$ESVERSION.noarch.rpm && wget https://download.elasticsearch.org/elasticsearch/elasticsearch/$package -O /tmp/$package && sudo rpm -Uvh /tmp/$package
--2015-08-02 20:27:24-- https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.7.1.noarch.rpm
Resolving download.elasticsearch.org... 174.129.211.252, 174.129.224.133, 23.21.179.119, ...
Connecting to download.elasticsearch.org|174.129.211.252|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 27323419 (26M) [application/x-redhat-package-manager]
Saving to: “/tmp/elasticsearch-1.7.1.noarch.rpm”
100%[===================================================>] 27,323,419 8.56M/s in 3.0s
2015-08-02 20:27:27 (8.56 MB/s) - “/tmp/elasticsearch-1.7.1.noarch.rpm” saved [27323419/27323419]
warning: /tmp/elasticsearch-1.7.1.noarch.rpm: Header V4 RSA/SHA1 Signature, key ID d88e42b4: NOKEY
Preparing... ########################################### [100%]
1:elasticsearch ########################################### [100%]
post remove script called with unknown argument `1'
warning: %postun(elasticsearch-1.7.0-1.noarch) scriptlet failed, exit status 1