add warning for known problematic env vars

scripts/newinstall.sh

@@ -784,6 +784,50 @@ n8l::install_eups() {
 	echo " done."
 }
 
+n8l::problem_vars() {
+	local problems=(
+		EUPS_PATH
+		EUPS_PKGROOT
+		LSST_HOME
+		REPOSITORY_PATH
+	)
+	local found=()
+
+	for v in ${problems[*]}; do
+		if [[ -n ${!v+1} ]]; then
+			found+=($v)
+		fi
+	done
+
+	echo -n "${found[@]}"
+}
+
+n8l::problem_vars_check() {
+	local problems=()
+	problems=($(n8l::problem_vars))
+
+	if [[ ${#problems} -gt 0 ]]; then
+		n8l::print_error "$(cat <<-EOF
+			WARNING: the following environment variables are defined that will affect
+			the operation of the LSST build tooling.\n
+			EOF
+		)"
+
+		for v in ${problems[*]}; do
+			n8l::print_error "${v}=\"${!v}\""
+		done
+
+		n8l::print_error "$(cat <<-EOF
+
+			It is recommended that they are undefined before running this script.
+
+			unset ${problems[*]}
+			EOF
+		)"
+		return 1
+	fi
+}
+
 n8l::generate_loader_bash() {
 	local file_name=$1
 
@@ -991,10 +1035,14 @@ n8l::main() {
 		n8l::up2date_check
 	fi
 
+	if [[ $BATCH_FLAG != true ]]; then
+		n8l::problem_vars_check
+	fi
+
 	n8l::git_check
 
 	# always use miniconda when in batch mode
-	if [[ $BATCH_FLAG = true ]]; then
+	if [[ $BATCH_FLAG == true ]]; then
 		WITH_MINICONDA=true
 	else
 		n8l::python_check

spec/unit/n8l/problem_vars_check_spec.rb

@@ -0,0 +1,56 @@
+require 'rspec/bash'
+
+describe 'n8l::problem_vars_check' do
+  include Rspec::Bash
+
+  let(:stubbed_env) { create_stubbed_env }
+  subject(:func) { 'n8l::problem_vars_check' }
+
+  let(:problems) do
+    %w[
+      EUPS_PATH
+      EUPS_PKGROOT
+      LSST_HOME
+      REPOSITORY_PATH
+    ]
+  end
+
+  context 'no problematic vars defined' do
+    it 'reports nothing' do
+      problem_vars = stubbed_env.stub_command('n8l::problem_vars')
+
+      out, err, status = stubbed_env.execute_function(
+        'scripts/newinstall.sh',
+        func,
+      )
+
+      expect(out).to eq('')
+      expect(err).to eq('')
+      expect(status.exitstatus).to be 0
+
+      expect(problem_vars).to be_called
+    end
+  end
+
+  context 'problematic vars defined' do
+    it 'prints multiple params to stderr' do
+      problem_vars = stubbed_env.stub_command('n8l::problem_vars').outputs(
+        problems.join(' ')
+      )
+
+      out, err, status = stubbed_env.execute_function(
+        'scripts/newinstall.sh',
+        <<-SCRIPT
+          #{problems.collect { |var| "#{var}=foo;" }.join(' ')}
+          #{func}
+        SCRIPT
+      )
+
+      expect(out).to eq('')
+      problems.each { |var| expect(err).to match(/#{var}="foo"/) }
+      expect(status.exitstatus).to_not be 0
+
+      expect(problem_vars).to be_called
+    end
+  end
+end

spec/unit/n8l/problem_vars_spec.rb

@@ -0,0 +1,51 @@
+require 'rspec/bash'
+
+describe 'n8l::problem_vars' do
+  include Rspec::Bash
+
+  let(:stubbed_env) { create_stubbed_env }
+  subject(:func) { 'n8l::problem_vars' }
+
+  let(:problems) do
+    %w[
+      EUPS_PATH
+      EUPS_PKGROOT
+      LSST_HOME
+      REPOSITORY_PATH
+    ]
+  end
+
+  context 'no problematic vars defined' do
+    it 'reports nothing' do
+      problems.each { |var| ENV.delete(var) }
+
+      out, err, status = stubbed_env.execute_function(
+        'scripts/newinstall.sh',
+        <<-SCRIPT
+          unset #{problems.join(' ')}
+          #{func}
+        SCRIPT
+      )
+
+      expect(out).to eq('')
+      expect(err).to eq('')
+      expect(status.exitstatus).to be 0
+    end
+  end
+
+  context 'problematic vars defined' do
+    it 'prints multiple params to stderr' do
+      out, err, status = stubbed_env.execute_function(
+        'scripts/newinstall.sh',
+        <<-SCRIPT
+          #{problems.collect { |var| "#{var}=foo;" }.join(' ')}
+          #{func}
+        SCRIPT
+      )
+
+      expect(out).to eq('EUPS_PATH EUPS_PKGROOT LSST_HOME REPOSITORY_PATH')
+      expect(err).to eq('')
+      expect(status.exitstatus).to be 0
+    end
+  end
+end