diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index d73e69b1237..b1fb3ec0cca 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -131,17 +131,18 @@ to nightly rustc).
 
 ## Logging
 
+
 Cargo uses [`env_logger`], so you can set
-`RUST_LOG` environment variable to get the logs. This is useful both for diagnosing
+`CARGO_LOG` environment variable to get the logs. This is useful both for diagnosing
 bugs in stable Cargo and for local development. Cargo also has internal hierarchical
 profiling infrastructure, which is activated via `CARGO_PROFILE` variable
 
 ```
 # Outputs all logs with levels debug and higher
-$ RUST_LOG=debug cargo generate-lockfile
+$ CARGO_LOG=debug cargo generate-lockfile
 
 # Don't forget that you can filter by module as well
-$ RUST_LOG=cargo::core::resolver=trace cargo generate-lockfile
+$ CARGO_LOG=cargo::core::resolver=trace cargo generate-lockfile
 
 # Output first three levels of profiling info
 $ CARGO_PROFILE=3 cargo generate-lockfile
diff --git a/src/bin/cargo/main.rs b/src/bin/cargo/main.rs
index d0a18293f6e..3ad505e4c55 100644
--- a/src/bin/cargo/main.rs
+++ b/src/bin/cargo/main.rs
@@ -18,9 +18,9 @@ use crate::command_prelude::*;
 
 fn main() {
     #[cfg(feature = "pretty-env-logger")]
-    pretty_env_logger::init();
+    pretty_env_logger::init_custom_env("CARGO_LOG");
     #[cfg(not(feature = "pretty-env-logger"))]
-    env_logger::init();
+    env_logger::init_from_env("CARGO_LOG");
     cargo::core::maybe_allow_nightly_features();
 
     let mut config = match Config::default() {
diff --git a/src/doc/src/reference/config.md b/src/doc/src/reference/config.md
index fb2da971b27..49d5a6519f5 100644
--- a/src/doc/src/reference/config.md
+++ b/src/doc/src/reference/config.md
@@ -113,7 +113,7 @@ multiplexing = true # whether or not to use HTTP/2 multiplexing where possible
 # This setting can be used to help debug what's going on with HTTP requests made
 # by Cargo. When set to `true` then Cargo's normal debug logging will be filled
 # in with HTTP information, which you can extract with
-# `RUST_LOG=cargo::ops::registry=debug` (and `trace` may print more).
+# `CARGO_LOG=cargo::ops::registry=debug` (and `trace` may print more).
 #
 # Be wary when posting these logs elsewhere though, it may be the case that a
 # header has an authentication token in it you don't want leaked! Be sure to
diff --git a/tests/testsuite/build.rs b/tests/testsuite/build.rs
index 2d1e47424f7..0b1fee4e657 100644
--- a/tests/testsuite/build.rs
+++ b/tests/testsuite/build.rs
@@ -2267,7 +2267,7 @@ fn simple_staticlib() {
         .build();
 
     // env var is a test for #1381
-    p.cargo("build").env("RUST_LOG", "nekoneko=trace").run();
+    p.cargo("build").env("CARGO_LOG", "nekoneko=trace").run();
 }
 
 #[test]
diff --git a/tests/testsuite/build_script.rs b/tests/testsuite/build_script.rs
index 9f33402928a..c511a3d2844 100644
--- a/tests/testsuite/build_script.rs
+++ b/tests/testsuite/build_script.rs
@@ -1547,13 +1547,13 @@ fn build_script_with_dynamic_native_dependency() {
 
     build
         .cargo("build -v")
-        .env("RUST_LOG", "cargo::ops::cargo_rustc")
+        .env("CARGO_LOG", "cargo::ops::cargo_rustc")
         .run();
 
     let root = build.root().join("target").join("debug");
     foo.cargo("build -v")
         .env("BUILDER_ROOT", root)
-        .env("RUST_LOG", "cargo::ops::cargo_rustc")
+        .env("CARGO_LOG", "cargo::ops::cargo_rustc")
         .run();
 }
 
@@ -2406,7 +2406,7 @@ fn fresh_builds_possible_with_link_libs() {
         .run();
 
     p.cargo("build -v")
-        .env("RUST_LOG", "cargo::ops::cargo_rustc::fingerprint=info")
+        .env("CARGO_LOG", "cargo::ops::cargo_rustc::fingerprint=info")
         .with_stderr(
             "\
 [FRESH] foo v0.5.0 ([..])
@@ -2461,7 +2461,7 @@ fn fresh_builds_possible_with_multiple_metadata_overrides() {
         .run();
 
     p.cargo("build -v")
-        .env("RUST_LOG", "cargo::ops::cargo_rustc::fingerprint=info")
+        .env("CARGO_LOG", "cargo::ops::cargo_rustc::fingerprint=info")
         .with_stderr(
             "\
 [FRESH] foo v0.5.0 ([..])
diff --git a/tests/testsuite/check.rs b/tests/testsuite/check.rs
index 06cd2c2fc27..54681bee008 100644
--- a/tests/testsuite/check.rs
+++ b/tests/testsuite/check.rs
@@ -740,7 +740,7 @@ fn proc_macro() {
             "#,
         )
         .build();
-    p.cargo("check -v").env("RUST_LOG", "cargo=trace").run();
+    p.cargo("check -v").env("CARGO_LOG", "cargo=trace").run();
 }
 
 #[test]
diff --git a/tests/testsuite/corrupt_git.rs b/tests/testsuite/corrupt_git.rs
index f71f2ec65b5..e27e8e15a0f 100644
--- a/tests/testsuite/corrupt_git.rs
+++ b/tests/testsuite/corrupt_git.rs
@@ -47,7 +47,7 @@ fn deleting_database_files() {
         }
         println!("deleting {}", file.display());
         cargopaths::remove_file(&file).unwrap();
-        project.cargo("build -v").env("RUST_LOG", log).run();
+        project.cargo("build -v").env("CARGO_LOG", log).run();
 
         if !file.exists() {
             continue;
@@ -60,7 +60,7 @@ fn deleting_database_files() {
             .unwrap()
             .set_len(2)
             .unwrap();
-        project.cargo("build -v").env("RUST_LOG", log).run();
+        project.cargo("build -v").env("CARGO_LOG", log).run();
     }
 }
 
@@ -124,7 +124,7 @@ fn deleting_checkout_files() {
         }
         println!("deleting {}", file.display());
         cargopaths::remove_file(&file).unwrap();
-        project.cargo("build -v").env("RUST_LOG", log).run();
+        project.cargo("build -v").env("CARGO_LOG", log).run();
 
         if !file.exists() {
             continue;
@@ -137,7 +137,7 @@ fn deleting_checkout_files() {
             .unwrap()
             .set_len(2)
             .unwrap();
-        project.cargo("build -v").env("RUST_LOG", log).run();
+        project.cargo("build -v").env("CARGO_LOG", log).run();
     }
 }
 
diff --git a/tests/testsuite/doc.rs b/tests/testsuite/doc.rs
index b073a070c82..eaee10aa884 100644
--- a/tests/testsuite/doc.rs
+++ b/tests/testsuite/doc.rs
@@ -132,7 +132,7 @@ fn doc_deps() {
     );
 
     p.cargo("doc")
-        .env("RUST_LOG", "cargo::ops::cargo_rustc::fingerprint")
+        .env("CARGO_LOG", "cargo::ops::cargo_rustc::fingerprint")
         .with_stdout("")
         .run();
 
diff --git a/tests/testsuite/freshness.rs b/tests/testsuite/freshness.rs
index 2ebb4affd86..b3ebe4b491c 100644
--- a/tests/testsuite/freshness.rs
+++ b/tests/testsuite/freshness.rs
@@ -759,7 +759,7 @@ fn rebuild_if_build_artifacts_move_forward_in_time() {
     p.root().move_into_the_future();
 
     p.cargo("build")
-        .env("RUST_LOG", "")
+        .env("CARGO_LOG", "")
         .with_stdout("")
         .with_stderr(
             "\
diff --git a/tests/testsuite/rustc_info_cache.rs b/tests/testsuite/rustc_info_cache.rs
index 257aea57a9d..5ecfb5f8ef0 100644
--- a/tests/testsuite/rustc_info_cache.rs
+++ b/tests/testsuite/rustc_info_cache.rs
@@ -13,7 +13,7 @@ fn rustc_info_cache() {
     let update = "[..]updated rustc info cache[..]";
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .with_stderr_contains("[..]failed to read rustc info cache[..]")
         .with_stderr_contains(miss)
         .with_stderr_does_not_contain(hit)
@@ -21,7 +21,7 @@ fn rustc_info_cache() {
         .run();
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .with_stderr_contains("[..]reusing existing rustc info cache[..]")
         .with_stderr_contains(hit)
         .with_stderr_does_not_contain(miss)
@@ -29,7 +29,7 @@ fn rustc_info_cache() {
         .run();
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .env("CARGO_CACHE_RUSTC_INFO", "0")
         .with_stderr_contains("[..]rustc info cache disabled[..]")
         .with_stderr_does_not_contain(update)
@@ -63,7 +63,7 @@ fn rustc_info_cache() {
     };
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .env("RUSTC", other_rustc.display().to_string())
         .with_stderr_contains("[..]different compiler, creating new rustc info cache[..]")
         .with_stderr_contains(miss)
@@ -72,7 +72,7 @@ fn rustc_info_cache() {
         .run();
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .env("RUSTC", other_rustc.display().to_string())
         .with_stderr_contains("[..]reusing existing rustc info cache[..]")
         .with_stderr_contains(hit)
@@ -83,7 +83,7 @@ fn rustc_info_cache() {
     other_rustc.move_into_the_future();
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .env("RUSTC", other_rustc.display().to_string())
         .with_stderr_contains("[..]different compiler, creating new rustc info cache[..]")
         .with_stderr_contains(miss)
@@ -92,7 +92,7 @@ fn rustc_info_cache() {
         .run();
 
     p.cargo("build")
-        .env("RUST_LOG", "cargo::util::rustc=info")
+        .env("CARGO_LOG", "cargo::util::rustc=info")
         .env("RUSTC", other_rustc.display().to_string())
         .with_stderr_contains("[..]reusing existing rustc info cache[..]")
         .with_stderr_contains(hit)
diff --git a/tests/testsuite/small_fd_limits.rs b/tests/testsuite/small_fd_limits.rs
index 273190810ca..2f49035b4cd 100644
--- a/tests/testsuite/small_fd_limits.rs
+++ b/tests/testsuite/small_fd_limits.rs
@@ -73,7 +73,7 @@ fn run_test(path_env: Option<&OsStr>) {
     if let Some(path) = path_env {
         cmd.env("PATH", path);
     }
-    cmd.env("RUST_LOG", "trace");
+    cmd.env("CARGO_LOG", "trace");
     cmd.run();
     let after = find_index()
         .join(".git/objects/pack")
diff --git a/tests/testsuite/update.rs b/tests/testsuite/update.rs
index 91b22fb6ca4..7a95c72cc0a 100644
--- a/tests/testsuite/update.rs
+++ b/tests/testsuite/update.rs
@@ -205,7 +205,7 @@ fn update_via_new_dep() {
     Package::new("log", "0.1.1").publish();
 
     p.uncomment_root_manifest();
-    p.cargo("build").env("RUST_LOG", "cargo=trace").run();
+    p.cargo("build").env("CARGO_LOG", "cargo=trace").run();
 }
 
 #[test]