Merge pull request #1 from marcstreeter/marcstreeter-alpine-linux-readme

Added alpine linux documentation

README.md

@@ -130,6 +130,13 @@ Running py-spy inside of a docker container will also usually bring up a permiss
 This error is caused by docker restricting the process_vm_readv system call we are using. This can be overridden by setting
 [```--cap-add SYS_PTRACE```](https://docs.docker.com/engine/security/seccomp/) when starting the docker container.
 
+
+### Running py-spy in Alpine Linux
+
+Alpine python opts out of the `manylinux` wheels: [pypa/pip#3969 (comment)](https://github.com/pypa/pip/issues/3969#issuecomment-247381915). Before installing py-spy on Alpine docker containers do:
+
+    echo 'manylinux1_compatible = True' > /usr/local/lib/python3.7/site-packages/_manylinux.py
+
 ### Running under Kubernetes
 
 py-spy needs `SYS_PTRACE` to be able to read process memory. Kubernetes drops that capability by default, resulting in the error