[nisaba] Use `required=True` instead of `mark_flag_as_required` in absl flags #2181

	name: "linux"

	on:
	push:
	branches: [ main ]
	pull_request:
	branches: [ main ]

	jobs:

	build-and-test-ubuntu:
	name: Build and Test (Ubuntu)
	runs-on: ubuntu-latest
	env:
	BAZEL: bazelisk-linux-amd64
	USE_BAZEL_VERSION: 6.4.0
	CC: gcc-10
	CXX: g++-10

	steps:
	- uses: actions/checkout@v3

	- name: Mount bazel cache
	uses: actions/cache@v3
	with:
	# See https://docs.bazel.build/versions/master/output_directories.html
	path: "~/.cache/bazel"
	key: ${{ runner.os }}-bazel-${{ hashFiles('WORKSPACE.bazel') }}
	restore-keys: ${{ runner.os }}-bazel

	- name: Install bazelisk
	run: \|
	curl -LO "https://github.com/bazelbuild/bazelisk/releases/latest/download/$BAZEL"
	chmod +x $BAZEL

	- name: Install requirements
	run: \|
	sudo apt-get update
	sudo apt-get install -y python3-pip python3-dev
	sudo pip install --upgrade pip
	sudo pip install -r ./requirements.txt

	- name: Environment variables (debug dump)
	run: \|
	echo "====== gcc version:"
	gcc --version
	echo "====== Requested gcc:"
	${CC} --version
	echo "====== g++ version:"
	g++ --version
	echo "====== Requested g++:"
	${CXX} --version

	- name: Cleanup disk space
	run: \|
	sudo rm -rf /usr/share/dotnet
	sudo rm -rf /opt/ghc
	sudo rm -rf /usr/local/share/boost
	sudo rm -rf "$AGENT_TOOLSDIRECTORY"

	- name: Build
	run: \|
	./$BAZEL run //:requirements.update
	./$BAZEL build -c opt //...

	- name: Test
	run: ./$BAZEL test -c opt --test_size_filters=-large,-enormous --test_output=errors //nisaba/...

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