From c3750edebb7e37a73571088cd93ff6032348863f Mon Sep 17 00:00:00 2001
From: Joe Rickerby <joerick@mac.com>
Date: Sun, 19 Jun 2022 10:45:07 +0100
Subject: [PATCH] Document use of pip options through environment variables

---
 docs/options.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/docs/options.md b/docs/options.md
index f72b388a..3f12ed8e 100644
--- a/docs/options.md
+++ b/docs/options.md
@@ -553,6 +553,10 @@ Platform-specific environment variables are also available:<br/>
     # Supply options to `pip` to affect how it downloads dependencies
     CIBW_ENVIRONMENT: PIP_EXTRA_INDEX_URL=https://pypi.myorg.com/simple
 
+    # Any pip command-line options can be set using the PIP_ prefix
+    # https://pip.pypa.io/en/stable/topics/configuration/#environment-variables
+    CIBW_ENVIRONMENT: PIP_GLOBAL_OPTION="build_ext -j4"
+
     # Set two flags on linux only
     CIBW_ENVIRONMENT_LINUX: BUILD_TIME="$(date)" SAMPLE_TEXT="sample text"
     ```
@@ -582,6 +586,10 @@ Platform-specific environment variables are also available:<br/>
     # Supply options to `pip` to affect how it downloads dependencies
     environment = { PIP_EXTRA_INDEX_URL="https://pypi.myorg.com/simple" }
 
+    # Any pip command-line option can be set using the PIP_ prefix
+    # https://pip.pypa.io/en/stable/topics/configuration/#environment-variables
+    environment = { PIP_GLOBAL_OPTION="build_ext -j4" }
+
     # Set two flags on linux only
     [tool.cibuildwheel.linux]
     environment = { BUILD_TIME="$(date)", SAMPLE_TEXT="sample text" }