add log feature as default so log and tracing can be used

Signed-off-by: simonsan <[email protected]>

crates/backend/Cargo.toml

@@ -31,7 +31,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [features]
-default = ["opendal", "rest", "rclone"]
+default = ["opendal", "rest", "rclone", "log"]
 cli = ["merge", "clap"]
 merge = ["dep:conflate"]
 clap = ["dep:clap"]
@@ -44,6 +44,9 @@ opendal = [
 ]
 rest = ["dep:reqwest", "dep:backoff"]
 rclone = ["rest", "dep:rand", "dep:semver"]
+# When the “log” feature is enabled, if no tracing Subscriber is active, invoking an event
+# macro or creating a span with fields will emit a log record.
+log = ["tracing/log"]
 
 [dependencies]
 # core

crates/core/Cargo.toml

@@ -29,11 +29,14 @@ harness = true
 edition = "2021"
 
 [features]
-default = []
+default = ["log"]
 cli = ["merge", "clap"]
 merge = ["dep:conflate"]
 clap = ["dep:clap"]
 webdav = ["dep:dav-server", "dep:futures"]
+# When the “log” feature is enabled, if no tracing Subscriber is active, invoking an event
+# macro or creating a span with fields will emit a log record.
+log = ["tracing/log"]
 
 [package.metadata.docs.rs]
 all-features = true