Installing postgres_exporter gives ERROR

[Junaid Subhani]

I am trying to build the postgres_exporter from the source (https://github.com/wrouesnel/postgres_exporter).

I downloaded the file and placed it in my go src directory. When I try to make the project, I get bunch of " warning: undeclared name: " 

What am I doing wrong here ? 

../os/user/lookup.go:11:41:warning: undeclared name: current (megacheck)
../os/user/lookup.go:32:9:warning: undeclared name: lookupUser (megacheck)
../os/user/lookup.go:41:9:warning: undeclared name: lookupUserId (megacheck)
../os/user/lookup.go:47:9:warning: undeclared name: lookupGroup (megacheck)
../os/user/lookup.go:53:9:warning: undeclared name: lookupGroupId (megacheck)
../net/lookup_unix.go:80:24:warning: undeclared name: cgoLookupHost (megacheck)
../net/lookup_unix.go:95:24:warning: undeclared name: cgoLookupIP (megacheck)
../net/lookup_unix.go:107:23:warning: undeclared name: cgoLookupPort (megacheck)
../net/lookup_unix.go:123:24:warning: undeclared name: cgoLookupCNAME (megacheck)
../net/lookup_unix.go:190:23:warning: undeclared name: cgoLookupPTR (megacheck)
../os/user/lookup.go:58:9:warning: unused struct field undeclared name: listGroups (structcheck)
../os/user/lookup.go:11:41:warning: unused struct field undeclared name: current (structcheck)
../os/user/lookup.go:32:9:warning: unused struct field undeclared name: lookupUser (structcheck)
../os/user/lookup.go:41:9:warning: unused struct field undeclared name: lookupUserId (structcheck)
../os/user/lookup.go:47:9:warning: unused struct field undeclared name: lookupGroup (structcheck)
../os/user/lookup.go:53:9:warning: unused struct field undeclared name: lookupGroupId (structcheck)
../net/lookup_unix.go:80:24:warning: unused struct field undeclared name: cgoLookupHost (structcheck)
../net/lookup_unix.go:95:24:warning: unused struct field undeclared name: cgoLookupIP (structcheck)
../net/lookup_unix.go:107:23:warning: unused struct field undeclared name: cgoLookupPort (structcheck)
../net/lookup_unix.go:123:24:warning: unused struct field undeclared name: cgoLookupCNAME (structcheck)
../net/lookup_unix.go:190:23:warning: unused struct field undeclared name: cgoLookupPTR (structcheck)
../os/user/lookup.go:58:9:warning: error return value not checked (undeclared name: listGroups) (errcheck)
../os/user/lookup.go:11:41:warning: error return value not checked (undeclared name: current) (errcheck)
../os/user/lookup.go:32:9:warning: error return value not checked (undeclared name: lookupUser) (errcheck)
../os/user/lookup.go:41:9:warning: error return value not checked (undeclared name: lookupUserId) (errcheck)
../os/user/lookup.go:47:9:warning: error return value not checked (undeclared name: lookupGroup) (errcheck)
../os/user/lookup.go:53:9:warning: error return value not checked (undeclared name: lookupGroupId) (errcheck)
../net/lookup_unix.go:80:24:warning: error return value not checked (undeclared name: cgoLookupHost) (errcheck)
../net/lookup_unix.go:95:24:warning: error return value not checked (undeclared name: cgoLookupIP) (errcheck)
../net/lookup_unix.go:107:23:warning: error return value not checked (undeclared name: cgoLookupPort) (errcheck)
../net/lookup_unix.go:123:24:warning: error return value not checked (undeclared name: cgoLookupCNAME) (errcheck)
../net/lookup_unix.go:190:23:warning: error return value not checked (undeclared name: cgoLookupPTR) (errcheck)
../os/user/lookup.go:58:9:warning: unused variable or constant undeclared name: listGroups (varcheck)
../os/user/lookup.go:11:41:warning: unused variable or constant undeclared name: current (varcheck)
../os/user/lookup.go:32:9:warning: unused variable or constant undeclared name: lookupUser (varcheck)
../os/user/lookup.go:41:9:warning: unused variable or constant undeclared name: lookupUserId (varcheck)
../os/user/lookup.go:47:9:warning: unused variable or constant undeclared name: lookupGroup (varcheck)
../os/user/lookup.go:53:9:warning: unused variable or constant undeclared name: lookupGroupId (varcheck)
../net/lookup_unix.go:80:24:warning: unused variable or constant undeclared name: cgoLookupHost (varcheck)
../net/lookup_unix.go:95:24:warning: unused variable or constant undeclared name: cgoLookupIP (varcheck)
../net/lookup_unix.go:107:23:warning: unused variable or constant undeclared name: cgoLookupPort (varcheck)
../net/lookup_unix.go:123:24:warning: unused variable or constant undeclared name: cgoLookupCNAME (varcheck)
../net/lookup_unix.go:190:23:warning: unused variable or constant undeclared name: cgoLookupPTR (varcheck)
../os/user/lookup.go:58:9:warning: undeclared name: listGroups (interfacer)
../os/user/lookup.go:11:41:warning: undeclared name: current (interfacer)
../os/user/lookup.go:32:9:warning: undeclared name: lookupUser (interfacer)
../os/user/lookup.go:41:9:warning: undeclared name: lookupUserId (interfacer)
../os/user/lookup.go:47:9:warning: undeclared name: lookupGroup (interfacer)
../os/user/lookup.go:53:9:warning: undeclared name: lookupGroupId (interfacer)
../net/lookup_unix.go:80:24:warning: undeclared name: cgoLookupHost (interfacer)
../net/lookup_unix.go:95:24:warning: undeclared name: cgoLookupIP (interfacer)
../net/lookup_unix.go:107:23:warning: undeclared name: cgoLookupPort (interfacer)
../net/lookup_unix.go:123:24:warning: undeclared name: cgoLookupCNAME (interfacer)
../net/lookup_unix.go:190:23:warning: undeclared name: cgoLookupPTR (interfacer)
make: *** [lint] Error 1

[Junaid Subhani]

I was able to solve this issue by installing "gcc" . Now when I want to run the exporter , this is the ERROR that I get. Any idea about the "panic: inconsistent label cardinality" ? 

DATA_SOURCE_NAME="postgresql://postgres:postgres@localhost:5432/?sslmode=disable"



# ./postgres_exporter
INFO[0000] Established new database connection.          source=postgres_exporter.go:951
INFO[0000] Semantic Version Changed: 0.0.0 -> 9.4.1      source=postgres_exporter.go:904
panic: inconsistent label cardinality


goroutine 17 [running]:
postgres_exporter-master/vendor/github.com/prometheus/client_golang/prometheus.MustNewConstMetric(0xc42021c770, 0x3, 0x0, 0xc42025b120, 0x2, 0x2, 0x0, 0x0)
 /usr/local/go/src/postgres_exporter-master/vendor/github.com/prometheus/client_golang/prometheus/value.go:172 +0xb3
main.queryNamespaceMapping(0xc420184000, 0xc42014e280, 0x7c9e3f, 0x10, 0xc420129180, 0x2, 0x2, 0xc420139500, 0xc420139b90, 0x0, ...)
 /usr/local/go/src/postgres_exporter-master/postgres_exporter.go:853 +0x1200
main.queryNamespaceMappings(0xc420184000, 0xc42014e280, 0xc4201391a0, 0xc420139b90, 0x0)
 /usr/local/go/src/postgres_exporter-master/postgres_exporter.go:868 +0x321
main.(*Exporter).scrape(0xc420182000, 0xc420184000)
 /usr/local/go/src/postgres_exporter-master/postgres_exporter.go:996 +0x58d
main.(*Exporter).Collect(0xc420182000, 0xc420184000)
 /usr/local/go/src/postgres_exporter-master/postgres_exporter.go:747 +0x39
main.(*Exporter).Describe(0xc420182000, 0xc420144120)
 /usr/local/go/src/postgres_exporter-master/postgres_exporter.go:740 +0xb0
postgres_exporter-master/vendor/github.com/prometheus/client_golang/prometheus.(*registry).Register.func1(0x97ab20, 0xc420182000, 0xc420144120)
 /usr/local/go/src/postgres_exporter-master/vendor/github.com/prometheus/client_golang/prometheus/registry.go:218 +0x3b
created by postgres_exporter-master/vendor/github.com/prometheus/client_golang/prometheus.(*registry).Register
 /usr/local/go/src/postgres_exporter-master/vendor/github.com/prometheus/client_golang/prometheus/registry.go:217 +0xbc

[0x00d...@gmail.com]

Hello!
Line bellow from the postgres_exporter documentation:

NOTE
Remember to use postgres database name in the connection string: