ad-hoc build script for pytorch 1.8.1 on alpine linux 3.13.4

alpine.patch

--- a/c10/macros/Macros.h
+++ b/c10/macros/Macros.h
@@ -287,12 +287,12 @@
     defined(__HIP_ARCH__) || defined(__HIP__)
 __host__ __device__
 #endif // __CUDA_ARCH__
-    void
+    _Noreturn void
     __assert_fail(
         const char* assertion,
         const char* file,
-        unsigned int line,
-        const char* function) throw();
+        int line,
+        const char* function);
 }
 #endif // NDEBUG
 #define CUDA_KERNEL_ASSERT(cond)                                         \
--- a/c10/util/Type.cpp
+++ b/c10/util/Type.cpp
@@ -10,7 +10,12 @@
     (TARGET_IPHONE_SIMULATOR || TARGET_OS_SIMULATOR || TARGET_OS_IPHONE)
 #define HAS_DEMANGLE 0
 #else
+#include <features.h>
+#if defined(__GLIBC__)
 #define HAS_DEMANGLE 1
+#else
+#define HAS_DEMANGLE 0
+#endif
 #endif
 
 #if HAS_DEMANGLE
--- a/torch/lib/libshm/core.cpp
+++ b/torch/lib/libshm/core.cpp
@@ -32,7 +32,7 @@
     SYSCHECK_ERR_RETURN_NEG1(close(pipe_ends[0]));
     SYSCHECK_ERR_RETURN_NEG1(dup2(pipe_ends[1], 1)); // Replace stdout
     SYSCHECK_ERR_RETURN_NEG1(close(pipe_ends[1]));
-    execl(manager_executable_path.c_str(), "torch_shm_manager", NULL);
+    execl(manager_executable_path.c_str(), "torch_shm_manager", (char*)NULL);
     exit(1);
   }
   SYSCHECK_ERR_RETURN_NEG1(close(pipe_ends[1]));
--- a/third_party/tensorpipe/tensorpipe/channel/cma/context_impl.cc
+++ b/third_party/tensorpipe/tensorpipe/channel/cma/context_impl.cc
@@ -8,7 +8,6 @@

 #include <tensorpipe/channel/cma/context_impl.h>

-#include <linux/prctl.h>
 #include <sys/prctl.h>
 #include <sys/uio.h>
 #include <unistd.h>

build

#!/usr/bin/env sh

set -e

cd "$(readlink -f "$(dirname "$0")" )"

for dependency in cmake g++ git linux-headers musl-dev openblas-dev patch py3-numpy py3-pip py3-requests py3-typing-extensions py3-wheel py3-yaml; do
  if ! apk info -e "$dependency" >/dev/null; then
    printf "\e[31m%s\e[0m%s\n" "Missing dependency, try:" " apk add $dependency" >&2
    exit 1
  fi
done

if which ccache >/dev/null; then
  mkdir -p bin
  [ -h bin/cc  ] || ln -s "$(which ccache)" bin/cc
  [ -h bin/c++ ] || ln -s "$(which ccache)" bin/c++
  [ -h bin/gcc ] || ln -s "$(which ccache)" bin/gcc
  [ -h bin/g++ ] || ln -s "$(which ccache)" bin/g++
  PATH="$(readlink -f bin):$PATH"
  export PATH
else
  # i'm not sure if ccache actually helps here.
  #printf "\e[93m%s\e[0m\n" "Warning: ccache is not installed." >&2
fi

mkdir -p pytorch
cd pytorch

get_commit() {
    # prints the hash of the specified ref, or nothing.
    git rev-parse -q "$1" -- 2>/dev/null | head -n1
}

# do some git magic to save tons of bandwidth and disk space
[ -d .git ] || git init
[ "$(git remote)" = "origin" ] || git remote add origin https://github.com/pytorch/pytorch
# this commit corresponds to the tag v1.8.1
commit=56b43f4fec1f76953f15a627694d4bba34588969
# specifying FETCH_HEAD doesn't work well with get_commit, so...
[ "$(get_commit HEAD)" = $commit ] || git fetch --depth 1 origin $commit

# magic part 2
[ "$(get_commit HEAD)" = $commit ] || git checkout FETCH_HEAD
# --force git to check out the files instead of just fetching
[ -e third_party/zstd/NEWS ] || git submodule update --init --recursive --depth=1 --force

# undo all changes so the patch has something clean to work with:
#git reset --hard
#git submodule foreach --recursive git reset --hard

# the -q shorthand doesn't exist for diff-index, for some reason.
if git diff-index --quiet HEAD --; then
    patch -p1 -i ../alpine.patch
fi

python3 setup.py build
python3 setup.py bdist_wheel
# install the most recent wheel (presumably the one we just built)
pip install "dist/$(ls -t dist | head -n1)"