The way cmake has been setup, it decides which version to compile for using that variable (if defined). If the variable is not defined, it locates pg_config and deduces version from it. 
We could add a default PG_CONFIG variable that links to the latest supported version. Created a JIRA for this.  

On Wed, Feb 8, 2017 at 3:10 PM, Jim Nasby <Jim.Nasby@bluetreble.com> wrote:
On 2/8/17 10:18 AM, Rahul Iyer wrote:
add `-DPOSTGRESQL_9_6_PG_CONFIG=/path/to/pg_config' with the `cmake ...`
command

Does that variable need to include the version number? Couldn't it just be called PG_CONFIG ?
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Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
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