diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index d73e69b1237..f0acf00ad7e 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -132,16 +132,16 @@ 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 39bc48f6887..02f77d99a0b 100644
--- a/src/bin/cargo/main.rs
+++ b/src/bin/cargo/main.rs
@@ -20,9 +20,9 @@ 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/cargo/core/compiler/build_context/target_info.rs b/src/cargo/core/compiler/build_context/target_info.rs
index 8a83643c4cf..b5d2f308a8b 100644
--- a/src/cargo/core/compiler/build_context/target_info.rs
+++ b/src/cargo/core/compiler/build_context/target_info.rs
@@ -75,7 +75,7 @@ impl TargetInfo {
             .arg("___")
             .arg("--print=file-names")
             .args(&rustflags)
-            .env_remove("RUST_LOG");
+            .env_remove("RUSTC_LOG");
 
         let target_triple = requested_target
             .as_ref()
diff --git a/src/cargo/core/compiler/fingerprint.rs b/src/cargo/core/compiler/fingerprint.rs
index ebad436df4e..e7f56b1eca6 100644
--- a/src/cargo/core/compiler/fingerprint.rs
+++ b/src/cargo/core/compiler/fingerprint.rs
@@ -79,7 +79,7 @@
 //!   quick loading and comparison.
 //! - A `.json` file that contains details about the Fingerprint. This is only
 //!   used to log details about *why* a fingerprint is considered dirty.
-//!   `RUST_LOG=cargo::core::compiler::fingerprint=trace cargo build` can be
+//!   `CARGO_LOG=cargo::core::compiler::fingerprint=trace cargo build` can be
 //!   used to display this log information.
 //! - A "dep-info" file which contains a list of source filenames for the
 //!   target. This is produced by reading the output of `rustc
@@ -936,7 +936,7 @@ impl DepFingerprint {
 impl StaleFile {
     /// Use the `log` crate to log a hopefully helpful message in diagnosing
     /// what file is considered stale and why. This is intended to be used in
-    /// conjunction with `RUST_LOG` to determine why Cargo is recompiling
+    /// conjunction with `CARGO_LOG` to determine why Cargo is recompiling
     /// something. Currently there's no user-facing usage of this other than
     /// that.
     fn log(&self) {
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 14e5263b929..20a97cfc549 100644
--- a/tests/testsuite/build.rs
+++ b/tests/testsuite/build.rs
@@ -2028,7 +2028,7 @@ 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 3303327fea9..8ed874321b4 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();
 }
 
@@ -2460,7 +2460,7 @@ 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 628fd807850..d75bd904711 100644
--- a/tests/testsuite/check.rs
+++ b/tests/testsuite/check.rs
@@ -730,7 +730,7 @@ 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 f821eed090d..1cfa9684879 100644
--- a/tests/testsuite/doc.rs
+++ b/tests/testsuite/doc.rs
@@ -115,7 +115,7 @@ fn doc_deps() {
     assert_eq!(p.glob("target/debug/deps/libbar-*.rmeta").count(), 1);
 
     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 0909313e219..91c2edbe7fd 100644
--- a/tests/testsuite/freshness.rs
+++ b/tests/testsuite/freshness.rs
@@ -760,7 +760,7 @@ 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/test.rs b/tests/testsuite/test.rs
index ac4c883a8a1..a5980a00901 100644
--- a/tests/testsuite/test.rs
+++ b/tests/testsuite/test.rs
@@ -3578,7 +3578,7 @@ test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
 
 ",
         )
-        .env("RUST_LOG", "cargo=trace")
+        .env("CARGO_LOG", "cargo=trace")
         .run();
 
     p.cargo("test --lib --doc")
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]