From c03219a8244e2a6d78ab71c916d4eb1353fb5ac6 Mon Sep 17 00:00:00 2001
From: Jon Gjengset <jongje@amazon.com>
Date: Tue, 11 Apr 2023 22:38:25 +0000
Subject: [PATCH] Recommend pointing binary-path at /deps

This results in a significant speed-up since we can avoid invoking
`llvm-cov export` on all the object files in `target/debug/incremental`.

See https://github.com/mozilla/grcov/issues/1013.
---
 README.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index e3ed2047f..dc5c726d6 100644
--- a/README.md
+++ b/README.md
@@ -258,7 +258,7 @@ RUSTC_BOOTSTRAP=1`, which basically turns your stable rustc into a Nightly one.
 Generate a html coverage report like this:
 
 ```sh
-grcov . -s . --binary-path ./target/debug/ -t html --branch --ignore-not-existing -o ./target/debug/coverage/
+grcov . -s . --binary-path ./target/debug/deps/ -t html --branch --ignore-not-existing -o ./target/debug/coverage/
 ```
 
 N.B.: The `--binary-path` argument is only necessary for source-based coverage.
@@ -282,7 +282,7 @@ LCOV output should be used when uploading to Codecov, with the `--branch` argume
 Coverage can also be generated in coveralls format:
 
 ```sh
-grcov . --binary-path ./target/debug/ -t coveralls -s . --token YOUR_COVERALLS_TOKEN > coveralls.json
+grcov . --binary-path ./target/debug/deps/ -t coveralls -s . --token YOUR_COVERALLS_TOKEN > coveralls.json
 ```
 
 #### grcov with Travis
@@ -305,7 +305,7 @@ script:
     - export RUSTFLAGS="-Cinstrument-coverage"
     - cargo build --verbose
     - LLVM_PROFILE_FILE="your_name-%p-%m.profraw" cargo test --verbose
-    - ./grcov . --binary-path ./target/debug/ -s . -t lcov --branch --ignore-not-existing --ignore "/*" -o lcov.info
+    - ./grcov . --binary-path ./target/debug/deps/ -s . -t lcov --branch --ignore-not-existing --ignore "/*" -o lcov.info
     - bash <(curl -s https://codecov.io/bash) -f lcov.info
 ```
 
@@ -358,7 +358,7 @@ build:
     # you expect, look for '.profraw' files in other directories.
         target/coverage
     # If your target dir is modified, this will need to match...
-        --binary-path target/debug
+        --binary-path target/debug/deps
     # Where the source directory is expected
         -s .
     # Where to write the output; this should be a directory that exists.