stricter dep vers in Cargo.toml to maintain MSRV

CHANGELOG.md

@@ -5,6 +5,7 @@ Dates are given in YYYY-MM-DD format.
 ### v0.3.4 (2021-mm-dd)
 #### Other
 - Refactored `formats.rs`
+- More accurate dependency versions in `Cargo.toml` to ensure that the MSRV stays supported
 
 ### v0.3.3 (2021-07-07)
 #### Features
@@ -95,7 +96,7 @@ Dates are given in YYYY-MM-DD format.
   (files without extensions are still skipped unless the -S flag is used)
 #### Bugfixes
 - Fixed compilation on big endian 32-bit architectures (see
-  [here](https://github.com/bodil/smartstring/blob/v0.2.6/src/config.rs#L101-L103) for why that was a problem in the
+  [here](https://github.com/bodil/smartstring/blob/v0.2.7/src/config.rs#L102-L104) for why that was a problem in the
   first place)
 - Fixed broken tests for the [`infer`] backend
 #### Other

Cargo.lock

@@ -569,9 +569,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.64"
+version = "1.0.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
+checksum = "336b10da19a12ad094b59d870ebde26a45402e5b470add4b5fd03c5048a32127"
 dependencies = [
  "itoa",
  "ryu",

Cargo.toml

@@ -46,7 +46,17 @@ xdg-mime = "0.3.3"
 infer = { version = "0.5.0", optional = true }
 
 [target.'cfg(not(all(target_endian = "big", target_pointer_width = "32")))'.dependencies]
-smartstring = "0.2.6"
+# the seemingly weird target constraint here is due to this:
+# https://github.com/bodil/smartstring/blob/v0.2.7/src/config.rs#L102-L104
+# essentially, smartstring is intentionally blocked from compiling on 32-bit big endian archs, so our dependency on it
+# needs to be too. otherwise, fif won't work on platforms like powerpc, even though this dependency is the only
+# blocker -- fif runs just fine on powerpc without smartstring. or at least, just fine under qemu user-mode powerpc ~u0
+
+# additionally, smartstring 0.2.8 requires rust >=1.46 (due to https://github.com/rust-lang/rust/issues/49146), and
+# 0.2.3 doesn't impl Display on its SmartString type.
+# so, we need at least 0.2.4 so we can println! strings, and at most 0.2.7 until we bump the MSRV to at least 1.46.
+# see https://github.com/bodil/smartstring/blob/master/CHANGELOG.md
+smartstring = "<= 0.2.7, >= 0.2.4"
 
 [dependencies.clap]
 version = "3.0.0-beta.2"