[Pljava-dev] mvn clean install fails for PL/Java on Postgres 9.5

Hello world,

I am working on installing PL/Java on Postgres 9.5.

My setup is Postgres 9.5 on Centos 6.5 with Oracle-Java JDK 1.8.0_92

My install of Postgres was done from these yum-packages:

postgresql95
postgresql95-devel
postgresql95-libs
postgresql95-server

I list below a summary of my steps so far:

su - postgres
git clone https://github.com/tada/pljava
git checkout V1_5_0
mvn clean install

That seemed to work until I saw this:

[INFO]
------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] PostgreSQL PL/Java ................................. SUCCESS [
16.707 s]
[INFO] PL/Java API ........................................ SUCCESS [
8.771 s]
[INFO] PL/Java backend Java code .......................... SUCCESS [
4.000 s]
[INFO] PL/Java backend native code ........................ FAILURE [
13.560 s]
[INFO] PL/Java Deploy ..................................... SKIPPED
[INFO] PL/Java Ant tasks .................................. SKIPPED
[INFO] PL/Java examples ................................... SKIPPED
[INFO] PL/Java packaging .................................. SKIPPED
[INFO]
------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO]
------------------------------------------------------------------------
[INFO] Total time: 52.707 s
[INFO] Finished at: 2016-07-06T18:09:40-07:00
[INFO] Final Memory: 38M/222M
[INFO]
------------------------------------------------------------------------

[ERROR] Failed to execute goal
com.github.maven-nar:nar-maven-plugin:3.2.3:nar-compile
(default-nar-compile) on project pljava-so: NAR: Compile failed: gcc
failed with return code 1 -> [Help 1]

[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with
the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions,
please read the following articles:
[ERROR] [Help 1]
http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with
the command
[ERROR] mvn <goals> -rf :pljava-so

I would welcome any clues and/or opinions about how to best debug this so
that mvn clean install will run error free.