diff --git a/.github/workflows/python.yml b/.github/workflows/python.yml
index 5a49848..23faaac 100644
--- a/.github/workflows/python.yml
+++ b/.github/workflows/python.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
 
     steps:
       - uses: actions/checkout@v2
@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.10"]
+        python-version: ["3.12"]
 
     steps:
       - uses: actions/checkout@v2
@@ -42,3 +42,23 @@ jobs:
       - name: Test with mypy
         run: |
           mypy --check-untyped-defs src/running
+  black:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.12"]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip setuptools build[virtualenv]
+          pip install .[zulip,tests]
+          pip install black
+      - name: Test with black
+        run: |
+          black --check src tests
diff --git a/docs/src/changelog.md b/docs/src/changelog.md
index 1575f36..3d1f50e 100644
--- a/docs/src/changelog.md
+++ b/docs/src/changelog.md
@@ -1,14 +1,20 @@
 # Changelog
 ## Unreleased
 ### Added
-#### Benchmark Suites
-- `DaCapo`: add 23.11-Chopin release and minheap values.
+#### Base Configurations
+- DaCapo 23.11-Chopin
+- Temurin 21
 
 ### Changed
+#### Base Configurations
+- Environment variables are expanded when resolving paths of runtimes and benchmark suites.
 
 ### Deprecated
+- Deprecating Python 3.7 support for users. Python 3.7 was last released on June 6, 2023 (3.7.17), which was recent.
 
 ### Removed
+- Dropping Python 3.6 support for users. Last Python 3.6 release was on Sept. 4, 2021 (3.6.15), which was long ago.
+- Dropping Python 3.7 support for developers (NOT users). pytest 7.4+ requires at least Python 3.8 (still supported by Ubuntu 20.04 LTS).
 
 ### Fixed
 
diff --git a/pyproject.toml b/pyproject.toml
index 81272a2..270c64c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,7 +20,7 @@ classifiers = [
 ]
 authors = [{name = "Zixian Cai", email = "u5937495@anu.edu.au"}]
 dependencies = [
-    "pyyaml~=6.0"
+    "pyyaml~=6.0.1"
 ]
 dynamic = ["version"]
 
@@ -30,12 +30,12 @@ dynamic = ["version"]
 
 [project.optional-dependencies]
 zulip = [
-    "zulip~=0.8.2"
+    "zulip~=0.9.0"
 ]
 tests = [
-    "pytest>=7.1.3,<7.5.0",
-    "types-PyYAML~=6.0.11",
-    "mypy>=0.971,<2.0"
+    "pytest~=7.4.3",
+    "types-PyYAML~=6.0.12",
+    "mypy~=1.7.0"
 ]
 
 [project.scripts]
diff --git a/src/running/benchmark.py b/src/running/benchmark.py
index 150b2ed..f448e9b 100644
--- a/src/running/benchmark.py
+++ b/src/running/benchmark.py
@@ -37,7 +37,7 @@ def __init__(
         runtime_specific_modifiers_strategy: Optional[
             Callable[[Runtime], Sequence[Modifier]]
         ] = None,
-        **kwargs
+        **kwargs,
     ):
         self.name = name
         self.suite_name = suite_name
diff --git a/src/running/command/log_preprocessor.py b/src/running/command/log_preprocessor.py
index 1a9599e..8eb1f1c 100644
--- a/src/running/command/log_preprocessor.py
+++ b/src/running/command/log_preprocessor.py
@@ -65,7 +65,7 @@ def ratio_work_perf_event(event_name: str):
 
     def inner(stats: Dict[str, float]):
         new_stats = deepcopy(stats)
-        for (k, v) in stats.items():
+        for k, v in stats.items():
             if compiled.match(k):
                 new_column = k.replace(".total", ".ratio")
                 new_stats[new_column] = v / stats[aggregated_column]
@@ -107,7 +107,7 @@ def calc_work_ipc(stats: Dict[str, float]):
     pattern = "work\\.\\w+\\.PERF_COUNT_HW_INSTRUCTIONS\\.total"
     compiled = re.compile(pattern)
     new_stats = deepcopy(stats)
-    for (k, v) in stats.items():
+    for k, v in stats.items():
         if compiled.match(k):
             cycles = k.replace("PERF_COUNT_HW_INSTRUCTIONS", "PERF_COUNT_HW_CPU_CYCLES")
             ipc = k.replace(
diff --git a/src/running/config/base/temurin.yml b/src/running/config/base/temurin.yml
index 9d5cc43..e749893 100644
--- a/src/running/config/base/temurin.yml
+++ b/src/running/config/base/temurin.yml
@@ -11,3 +11,7 @@ runtimes:
     type: OpenJDK
     release: 17
     home: /usr/lib/jvm/temurin-17-jdk-amd64
+  temurin-21:
+    type: OpenJDK
+    release: 21
+    home: /usr/lib/jvm/temurin-21-jdk-amd64
diff --git a/src/running/runtime.py b/src/running/runtime.py
index e6f0286..b7e2115 100644
--- a/src/running/runtime.py
+++ b/src/running/runtime.py
@@ -3,6 +3,7 @@
 from pathlib import Path
 import logging
 from running.util import register
+import os.path
 
 
 class Runtime(object):
@@ -90,7 +91,7 @@ def __init__(self, **kwargs):
         except ValueError:
             raise TypeError("The release of an OpenJDK has to be int-like")
         self.home: Path
-        self.home = Path(kwargs["home"])
+        self.home = Path(os.path.expandvars(kwargs["home"]))
         if not self.home.exists():
             logging.warning("OpenJDK home {} doesn't exist".format(self.home))
         self.executable = self.home / "bin" / "java"
@@ -110,7 +111,7 @@ class JikesRVM(JVM):
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         self.home: Path
-        self.home = Path(kwargs["home"])
+        self.home = Path(os.path.expandvars(kwargs["home"]))
         if not self.home.exists():
             logging.warning("JikesRVM home {} doesn't exist".format(self.home))
         self.executable = self.home / "rvm"
@@ -129,7 +130,7 @@ class JavaScriptRuntime(Runtime):
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         self.executable: Path
-        self.executable = Path(kwargs["executable"])
+        self.executable = Path(os.path.expandvars(kwargs["executable"]))
         if not self.executable.exists():
             logging.warning(
                 "JavaScriptRuntime executable {} doesn't exist".format(self.executable)
@@ -204,7 +205,7 @@ class Julia(Runtime):
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         self.executable: Path
-        self.executable = Path(kwargs["executable"])
+        self.executable = Path(os.path.expandvars(kwargs["executable"]))
         if not self.executable.exists():
             logging.warning("Julia executable {} doesn't exist".format(self.executable))
         self.executable = self.executable.absolute()
diff --git a/src/running/suite.py b/src/running/suite.py
index c97d33a..aec5661 100644
--- a/src/running/suite.py
+++ b/src/running/suite.py
@@ -11,6 +11,7 @@
 from running.modifier import JVMArg, Modifier
 import logging
 from running.util import register, split_quoted
+import os.path
 
 __DRY_RUN = False
 __DEFAULT_MINHEAP = 4096
@@ -112,7 +113,7 @@ def __init__(self, **kwargs):
         if self.release not in ["2006", "9.12", "evaluation"]:
             raise ValueError("DaCapo release {} not recongized".format(self.release))
         self.path: Path
-        self.path = Path(kwargs["path"])
+        self.path = Path(os.path.expandvars(kwargs["path"]))
         if not self.path.exists():
             logging.warning("DaCapo jar {} not found".format(self.path))
         self.minheap: Optional[str]
@@ -306,7 +307,7 @@ def __init__(self, **kwargs):
                 "SPECjbb2015 release {} not recongized".format(self.release)
             )
         self.path: Path
-        self.path = Path(kwargs["path"]).resolve()
+        self.path = Path(os.path.expandvars(kwargs["path"])).resolve()
         self.propsfile = (self.path / ".." / "config" / "specjbb2015.props").resolve()
         if not self.path.exists():
             logging.info("SPECjbb2015 jar {} not found".format(self.path))
@@ -349,7 +350,7 @@ class Octane(BenchmarkSuite):
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         self.path: Path
-        self.path = Path(kwargs["path"]).resolve()
+        self.path = Path(os.path.expandvars(kwargs["path"])).resolve()
         if not self.path.exists():
             logging.info("Octane folder {} not found".format(self.path))
         self.wrapper: Path
@@ -431,7 +432,7 @@ def __init__(self, **kwargs):
         if self.release not in ["1.03_05"]:
             raise ValueError("SPECjvm98 release {} not recongized".format(self.release))
         self.path: Path
-        self.path = Path(kwargs["path"]).resolve()
+        self.path = Path(os.path.expandvars(kwargs["path"])).resolve()
 
         if not self.path.exists():
             logging.info("SPECjvm98 {} not found".format(self.path))
@@ -481,7 +482,7 @@ class JuliaGCBenchmarks(BenchmarkSuite):
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         self.path: Path
-        self.path = Path(kwargs["path"])
+        self.path = Path(os.path.expandvars(kwargs["path"]))
         if not self.path.exists():
             logging.warning("JuliaGCBenchmarks does not exist at {}".format(self.path))
         self.minheap: Optional[str]
diff --git a/tests/test_runtime.py b/tests/test_runtime.py
new file mode 100644
index 0000000..843359e
--- /dev/null
+++ b/tests/test_runtime.py
@@ -0,0 +1,29 @@
+from running.config import Configuration
+
+
+def test_openjdk_path_ennvvar():
+    c = Configuration(
+        {
+            "runtimes": {
+                "temurin-21_bogus": {
+                    "type": "OpenJDK",
+                    "release": 21,
+                    # some bogus environment variable that will not be expanded
+                    "home": "$DAHKDLHDIWHEIUWHEIWEHIJHDJKAGDKJADGUQDGIQUWDGI/temurin-21-jdk-amd64",
+                },
+                "temurin-21": {
+                    "type": "OpenJDK",
+                    "release": 21,
+                    "home": "$HOME/temurin-21-jdk-amd64",
+                },
+            }
+        }
+    )
+
+    c.resolve_class()
+    temurin_21_bogus = c.get("runtimes")["temurin-21_bogus"]
+    temurin_21 = c.get("runtimes")["temurin-21_bogus"]
+    assert "$HOME" not in str(temurin_21.home)
+    assert "$DAHKDLHDIWHEIUWHEIWEHIJHDJKAGDKJADGUQDGIQUWDGI" in str(
+        temurin_21_bogus.home
+    )
diff --git a/tests/test_suite.py b/tests/test_suite.py
index f5c2215..0105cd9 100644
--- a/tests/test_suite.py
+++ b/tests/test_suite.py
@@ -116,3 +116,33 @@ def test_dacapo_openjdk_9_workaround():
     print(fop_jdk11.to_string(jdk11))
     assert "add-exports" not in fop_jdk8.to_string(jdk8)
     assert "add-exports" in fop_jdk11.to_string(jdk11)
+
+
+def test_dacapo_path_ennvvar():
+    c = Configuration(
+        {
+            "suites": {
+                "dacapo2006_bogus": {
+                    "type": "DaCapo",
+                    "release": "2006",
+                    # some bogus environment variable that will not be expanded
+                    "path": "$DAHKDLHDIWHEIUWHEIWEHIJHDJKAGDKJADGUQDGIQUWDGI/dacapo-2006-10-MR2.jar",
+                    "timing_iteration": 3,
+                },
+                "dacapo2006": {
+                    "type": "DaCapo",
+                    "release": "2006",
+                    "path": "$HOME/dacapo-2006-10-MR2.jar",
+                    "timing_iteration": 3,
+                },
+            }
+        }
+    )
+
+    c.resolve_class()
+    dacapo2006 = c.get("suites")["dacapo2006"]
+    dacapo2006_bogus = c.get("suites")["dacapo2006_bogus"]
+    assert "$HOME" not in str(dacapo2006.path)
+    assert "$DAHKDLHDIWHEIUWHEIWEHIJHDJKAGDKJADGUQDGIQUWDGI" in str(
+        dacapo2006_bogus.path
+    )