Document minimum stable Rust version (fixes #155)

README.md

@@ -16,7 +16,7 @@
 
 `pgx` supports Postgres v10, v11, v12, and v13.
 
-Feel free to join our [Discord Server](https://discord.gg/hPb93Y9).
+**Feel free to join our [Discord Server](https://discord.gg/hPb93Y9).**
 
 ## Key Features
 
@@ -114,13 +114,16 @@ custom types.
 
 ## System Requirements
 
- - `cargo install rustfmt`
+- `rustc` (minimum version 1.52) and `cargo` 
+- `cargo install rustfmt`
  - `git`
  - `libclang.so`
    - Ubuntu: `libclang-dev` or `clang`
    - RHEL: `clang`
  - [build dependencies for PostgreSQL](https://wiki.postgresql.org/wiki/Compile_and_Install_from_source_code)
 
+Note that a local Postgres installation is not required. `pgx` will download and compile Postgres itself.
+
 ## Getting Started
 
 ### 1. Install `cargo-pgx`
@@ -181,22 +184,35 @@ The first time, compilation takes a few minutes as `pgx` needs to generate almos
 Postgres' header files.
 
 Once compiled you'll be placed in a `psql` shell, for, in this case, Postgres 13.
-Now, we can just [load the extension](https://www.postgresql.org/docs/13/sql-createextension.html) and do a select on the example function.
-
-```sql
-CREATE EXTENSION my_extension;
-SELECT hello_my_extension();
-```
+Now, we can [load the extension](https://www.postgresql.org/docs/13/sql-createextension.html) and do a SELECT on the example function.
 
-This will return something along the lines of
+```console
+my_extension=# CREATE EXTENSION my_extension;
+CREATE EXTENSION
 
-```
+my_extension=# SELECT hello_my_extension();
  hello_my_extension
 ---------------------
  Hello, my_extension
 (1 row)
 ```
 
+
+## Upgrading
+
+You can upgrade your current `cargo-pgx` installation by passing the `--force` flag
+to `cargo install`:
+
+```shell script
+$ cargo install --force cargo-pgx
+```
+
+As new Postgres versions are supported by `pgx`, you can re-run the `pgx init` process to download and compile them:
+
+```shell script
+$ cargo pgx init
+```
+
 ## Digging Deeper
 
  - [cargo-pgx sub-command](cargo-pgx/)

pgx-macros/src/lib.rs

@@ -16,7 +16,7 @@ use std::collections::HashSet;
 use syn::spanned::Spanned;
 use syn::{parse_macro_input, Attribute, Data, DeriveInput, Item, ItemFn};
 
-/// Declare a function as `#[pg_guard]` to indcate that it is called from a Postgres `extern "C"`
+/// Declare a function as `#[pg_guard]` to indicate that it is called from a Postgres `extern "C"`
 /// function so that Rust `panic!()`s (and Postgres `elog(ERROR)`s) will be properly handled by `pgx`
 #[proc_macro_attribute]
 pub fn pg_guard(_attr: TokenStream, item: TokenStream) -> TokenStream {