release process: add sanity checks

Author: jonasnick

doc/release-process.md

@@ -12,6 +12,26 @@ It is best if the maintainers are present during the release, so they can help e
 
 This process also assumes that there will be no minor releases for old major releases.
 
+## Sanity Checks
+Perform these checks before creating a release:
+
+1. Ensure `make distcheck` doesn't fail.
+```shell
+make distcheck
+```
+2. Check installation with autotools:
+```shell
+dir=$(mktemp -d)
+./configure --prefix=$dir && make install && ls -l $dir/include $dir/lib
+gcc -o ecdsa ecdsa.c -I $dir/include -L $dir/lib64/ -l secp256k1
+```
+3. Check installation with CMake:
+```
+dir=$(mktemp -d)
+mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX=$dir .. && make install && ls -l $dir/include $dir/lib64
+gcc -o ecdsa ecdsa.c -I $dir/include -L $dir/lib64/ -l secp256k1
+```
+
 ## Regular release
 
 1. Open a PR to the master branch with a commit (using message `"release: prepare for $MAJOR.$MINOR.$PATCH"`, for example) that