Remove remnants of sccache (#629)

Before commit 71882f2 (May 2022), we
built LLVM from source. This employed sccache to make builds faster.

After that commit, sccache hasn't effectively been used. But there were
remnants of sccache in the code base.

This commit removes all references to sccache in the repo.

Author: indygreg

cpython-unix/build-binutils.sh

@@ -5,23 +5,12 @@
 
 set -ex
 
-ROOT=$(pwd)
-SCCACHE="${ROOT}/sccache"
-
 cd /build
 
 tar -xf binutils-${BINUTILS_VERSION}.tar.xz
 mkdir binutils-objdir
 pushd binutils-objdir
 
-EXTRA_VARS=
-
-if [ -x "${SCCACHE}" ]; then
-  "${SCCACHE}" --start-server
-  export CC="${SCCACHE} /usr/bin/gcc"
-  export STAGE_CC_WRAPPER="${SCCACHE}"
-fi
-
 # gprofng requires a bison newer than what we have. So just disable it.
 ../binutils-${BINUTILS_VERSION}/configure \
     --build=x86_64-unknown-linux-gnu \

cpython-unix/build.py

@@ -64,34 +64,6 @@
 MACOS_ALLOW_FRAMEWORKS = {"CoreFoundation"}
 
 
-def install_sccache(build_env):
-    """Attempt to install sccache into the build environment.
-
-    This will attempt to locate a sccache executable and copy it
-    into the root directory of the build environment.
-    """
-    candidates = [
-        # Prefer a binary in the project itself.
-        ROOT / "sccache",
-    ]
-
-    # Look for sccache in $PATH, but only if the build environment
-    # isn't isolated, as copying binaries into an isolated environment
-    # may not run. And running sccache in an isolated environment won't
-    # do anything meaningful unless an external cache is being used.
-    if not build_env.is_isolated:
-        for path in os.environ.get("PATH", "").split(":"):
-            if not path:
-                continue
-
-            candidates.append(pathlib.Path(path) / "sccache")
-
-    for candidate in candidates:
-        if candidate.exists():
-            build_env.copy_file(candidate)
-            return
-
-
 def add_target_env(env, build_platform, target_triple, build_env):
     add_env_common(env)
 
@@ -302,8 +274,6 @@ def build_binutils(client, image, host_platform):
     archive = download_entry("binutils", DOWNLOADS_PATH)
 
     with build_environment(client, image) as build_env:
-        install_sccache(build_env)
-
         build_env.copy_file(archive)
         build_env.copy_file(SUPPORT / "build-binutils.sh")
 

cpython-unix/sccache-wrapper.sh

@@ -104,38 +104,3 @@ You will need to specify the path to a ``sh.exe`` installed from cygwin. e.g.
 
 To build a 32-bit x86 binary, simply use an ``x86 Native Tools
 Command Prompt`` instead of ``x64``.
-
-Using sccache to Speed up Builds
-================================
-
-Builds can take a long time.
-
-python-build-standalone can automatically detect and use the
-`sccache <https://github.com/mozilla/sccache>`_ compiler cache to speed
-up subsequent builds on UNIX-like platforms. ``sccache`` can shave dozens
-of minutes from fresh builds, even on a 16 core CPU!
-
-If there is an executable ``sccache`` in the source directory, it will
-automatically be copied into the build environment and used. For non-container
-builds, an ``sccache`` executable is also searched for on ``PATH``.
-
-The ``~/.python-build-standalone-env`` file is read if it exists (the format is
-``key=value`` pairs) and variables are added to the build environment.
-
-In addition, environment variables ``AWS_ACCESS_KEY_ID``,
-``AWS_SECRET_ACCESS_KEY``, and any variable beginning with ``SCCACHE_`` are
-automatically added to the build environment.
-
-The environment variable support enables you to define remote build caches
-(such as S3 buckets) to provide a persistent, shared cache across builds and
-machines.
-
-Keep in mind that when performing builds in containers in Linux (the default
-behavior), the local filesystem is local to the container and does not survive
-the build of a single package. So sccache is practically meaningless unless
-configured to use an external store (such as S3).
-
-When using remote stores (such as S3), ``sccache`` can be constrained on
-network I/O. We recommend having at least a 100mbps network connection to
-a remote store and employing a network store with as little latency as possible
-for best results.

docs/building.rst

@@ -570,17 +570,6 @@ def add_env_common(env):
     except FileNotFoundError:
         pass
 
-    # Proxy sccache settings.
-    for k, v in os.environ.items():
-        if k.startswith("SCCACHE_"):
-            env[k] = v
-
-    # Proxy cloud provider credentials variables to enable sccache to
-    # use stores in those providers.
-    for k in ("AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY"):
-        if k in os.environ:
-            env[k] = os.environ[k]
-
 
 def exec_and_log(args, cwd, env):
     p = subprocess.Popen(

pythonbuild/utils.py

@@ -209,7 +209,7 @@ pub async fn command_fetch_release_distributions(args: &ArgMatches) -> Result<()
         for artifact in artifacts {
             if matches!(
                 artifact.name.as_str(),
-                "pythonbuild" | "sccache" | "toolchain"
+                "pythonbuild" | "toolchain"
             ) || artifact.name.contains("install-only")
             {
                 continue;