falco: Unable to run Regression test on host after build from source.

What happened: Tried running Regression test using command ./test/run_regression_tests.sh $PWD/build. The test case execution gave following error.

JOB LOG    : /root/falco/test/job-results/job-2019-08-27T10.37-c4333bd/job.log
Error running method "initialize" of plugin "yaml_to_mux": 'Namespace' object has no attribute 'get'
 (1/1) /root/falco/test/falco_test.py:FalcoTest.test: ERROR: [Errno 2] No such file or directory (/build/release/userspace/falco/falco -r /root/falco/test/../rules/falco_rules.yaml   -c /root/falco/test/../falco.yaml  -o json_output=False -o json_include_output_property=True -o priority=debug -v) (0.04 s)
RESULTS    : PASS 0 | ERROR 1 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB TIME   : 0.16 s

What you expected to happen: Successful execution of tests.

How to reproduce it (as minimally and precisely as possible): After Complete build. Follow steps from falco documentation to run test cases.( https://falco.org/docs/source/#run-the-tests )

Anything else we need to know?: Looks like it is searching for specific folder structure (build/release/<some files>). Observed that release directory did not get created after building falco.

Environment:

• Falco version (use falco --version): 0.17.0

• OS (e.g: cat /etc/os-release):

VERSION="18.04.2 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.2 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

• Kernel (e.g. uname -a): Linux ************** 4.15.0-52-generic #56-Ubuntu SMP Tue Jun 4 22:49:08 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

• Install tools (e.g. in kubernetes, rpm, deb, from source): Build from Source.