Make sed command work on both linux and mac
Bug: 53031
Change-Id: I46bc08bfa7e2254e03aaff8d8811cf4b40fd0cf2
diff --git a/README.md b/README.md
index 8dbfc7f..7bafbce 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,10 @@
```sh
BLACK_VERSION=$(pip3 install black== 2>&1 | grep versions: | sed -E 's/.*, ([a-z0-9\.]+)\)/\1/')
-sed -E -e "s/black==[^\"]+\"/black==${BLACK_VERSION}\"/" -i '' ./pyoxidizer.bzl
+# We have to specify a back-up to make this work on both Linux and MacOS:
+# https://stackoverflow.com/questions/5694228/sed-in-place-flag-that-works-both-on-mac-bsd-and-linux
+sed -E -e "s/black==[^\"]+\"/black==${BLACK_VERSION}\"/" -i.bak ./pyoxidizer.bzl
+rm ./pyoxidizer.bzl.bak
pyoxidizer build install
OS=$(if [[ $(uname) == 'Darwin' ]]; then echo 'mac'; else echo 'linux'; fi)
cipd create -tag version:${BLACK_VERSION} -pkg-def ./cipd-${OS}.yaml
