After building WildFly 14 from sources I have a lot of files in /var/tmp folder under a unique folder.
{{sb2000.[neu2l]/mbi/mbi2e_all. ls -l /var/tmp
total 5356
drwxr-xr-x 3 jboss informix 512 Oct 6 14:47 1397ea75-a91c-490a-9860-0041c101ef3a
drwxr-xr-x 3 jboss informix 512 Oct 6 13:47 23d28bb9-0bdd-4991-aa9b-8805d613e720
drwxr-xr-x 3 jboss informix 512 Oct 5 23:34 2c3bd18e-8b83-46d3-b06f-18378e1cb12d
drwxr-xr-x 3 jboss informix 512 Oct 6 14:56 396f75f7-45b0-4b50-9607-9060cabf018b
drwxr-xr-x 3 jboss informix 512 Oct 6 13:48 521e2a76-764c-4f5a-8a6e-282dd5978991
drwxr-xr-x 3 jboss informix 512 Oct 5 23:35 5430e295-1afa-4257-a2e0-e08b980b7e35
drwxr-xr-x 3 jboss informix 512 Oct 6 14:53 5a265551-8f04-48c9-8945-abf830e54852
drwxr-xr-x 3 jboss informix 512 Oct 6 13:46 70a1f863-7e84-40df-9206-23690bcf3ef6
drwxr-xr-x 3 jboss informix 512 Oct 5 22:02 7186627a-5a89-4334-bdc2-8bfb944e3841
drwxr-xr-x 3 jboss informix 512 Oct 6 14:52 85663b19-7e4e-48e9-8988-bd24c11fe4d4
drwxr-xr-x 3 jboss informix 512 Oct 5 23:39 8842f374-85b7-4018-a1fc-6274cb704785
drwxr-xr-x 3 jboss informix 512 Oct 5 22:05 973d7e32-efe5-4ffa-8f02-079cb7f29e71
drwxr-x--- 3 oracle dba 2560 Aug 30 00:00 CVU_18.0.0.0.0_oracle
drwxr-xr-x 3 jboss informix 512 Oct 5 22:06 b8975817-9381-41a3-a512-e8fc6596fa7a
drwxr-xr-x 3 jboss informix 512 Oct 6 13:40 bd0c1dd7-e8c6-413d-b658-f3c5236bba34
drwxr-xr-x 3 jboss informix 512 Oct 6 14:54 c3aa3f01-66df-4066-bb35-fed4bd0ad559
drwxr-xr-x 3 jboss informix 512 Oct 5 23:32 c66c2972-ad28-49e9-a7ff-a7ceed5b7ea3
drwxr-xr-x 3 jboss informix 512 Oct 5 23:24 ca8816d8-ad10-4860-a18b-0c09b37ed88b
drwxr-xr-x 3 jboss informix 512 Oct 6 13:50 cc799f82-ed02-4dc4-b56e-ffe0d8eeab75
drwx------ 2 langfr staff 512 Nov 15 2006 orbit-lafr
rw-rw-rw 1 langfr staff 2383862 Oct 5 03:17 patchdiag.xref
rw------ 1 root root 314461 Oct 6 15:32 wscon-:0-5saqic}}

{{sb2000.[neu2l]/var/tmp. ls -l 396f75f7-45b0-4b50-9607-9060cabf018b/maven/org.jboss.universe_community-universe/*/current
396f75f7-45b0-4b50-9607-9060cabf018b/maven/org.jboss.universe_community-universe/wildfly-core/current:
total 2
drwxr-xr-x 7 jboss informix 512 Oct 6 14:55 6.0.2.Final

396f75f7-45b0-4b50-9607-9060cabf018b/maven/org.jboss.universe_community-universe/wildfly-servlet/current:
total 2
drwxr-xr-x 6 jboss informix 512 Oct 6 14:55 14.0.1.Final

396f75f7-45b0-4b50-9607-9060cabf018b/maven/org.jboss.universe_community-universe/wildfly/current:
total 2
drwxr-xr-x 6 jboss informix 512 Oct 6 14:55 14.0.1.Final}}

Created by galleon feature pack build (galleon-pack/wildfly-feature-pack-build.xml).