Example from the guide not working?

[kirs]

I copied the project from examples/postgres/getting_started_step_3/ and prepared .env, but there's something about infer_schema! that fails on compile:

$ cargo install
   Compiling diesel_demo_step_3_pg v0.1.0 (file:///Users/kir/Projects/opensource/diesel_start)
error: custom derive attribute panicked
 --> src/schema.rs:1:1
  |
1 | infer_schema!("dotenv:DATABASE_URL");
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = help: message: assertion failed: !p.is_null()
  = note: this error originates in a macro outside of the current crate

error: failed to compile `diesel_demo_step_3_pg v0.1.0 (file:///Users/kir/Projects/opensource/diesel_start)`, intermediate artifacts can be found at `/Users/kir/Projects/opensource/diesel_start/target`

Caused by:
  Could not compile `diesel_demo_step_3_pg`.

To learn more, run the command again with --verbose.

However the .env is valid:

$ cat .env
DATABASE_URL=postgres://kir@localhost/diesel_demo

$ psql --user kir diesel_demo
psql (9.6.1)
Type "help" for help.

I also tried running DATABASE_URL=... cargo install but it causes the same error.

I checked that maybe infer_schema! usage have changed from the previous version and the code from the guide is using outdates API, but looking at diesel_tests/tests/schema.rs I see nothing wrong.

cc @sgrif

[sgrif]

Can you run cargo clean and then paste the output of cargo install --verbose?

[sgrif]

Also make sure you cargo update

[kirs]

https://gist.github.com/9396e192b68cabf13c54820238b39c58

[sgrif]

Hm. That assertion is coming from somewhere other than Diesel. Can you run again with RUST_BACKTRACE=1?

[kirs]

BTW, I'm running rust 1.15.1.

$ cargo update
    Updating registry `https://github.com/rust-lang/crates.io-index`

$ RUST_BACKTRACE=1 cargo install --verbose
       Fresh byteorder v1.0.0
       Fresh utf8-ranges v0.1.3
       Fresh winapi-build v0.1.1
       Fresh libc v0.2.20
       Fresh winapi v0.2.8
       Fresh regex-syntax v0.3.9
       Fresh quote v0.3.13
       Fresh unicode-xid v0.0.4
       Fresh memchr v0.1.11
       Fresh synom v0.11.0
       Fresh aho-corasick v0.5.3
       Fresh pq-sys v0.4.2
       Fresh syn v0.11.6
       Fresh kernel32-sys v0.2.2
       Fresh diesel v0.11.2
       Fresh thread-id v2.0.0
       Fresh diesel_infer_schema v0.11.0
       Fresh thread_local v0.2.7
       Fresh regex v0.1.80
       Fresh dotenv v0.8.0
       Fresh diesel_codegen v0.11.0
   Compiling diesel_demo_step_3_pg v0.1.0 (file:///Users/kir/Projects/opensource/diesel_start)
     Running `rustc --crate-name diesel_demo_step_3_pg src/lib.rs --crate-type lib -C opt-level=3 -C metadata=a7e40dfea0887d49 -C extra-filename=-a7e40dfea0887d49 --out-dir /Users/kir/Projects/opensource/diesel_start/target/release/deps --emit=dep-info,link -L dependency=/Users/kir/Projects/opensource/diesel_start/target/release/deps --extern dotenv=/Users/kir/Projects/opensource/diesel_start/target/release/deps/libdotenv-c0ef68bcfc5b2489.rlib --extern diesel_codegen=/Users/kir/Projects/opensource/diesel_start/target/release/deps/libdiesel_codegen-eefe7fa2e56aaa65.dylib --extern diesel=/Users/kir/Projects/opensource/diesel_start/target/release/deps/libdiesel-82ac424c6bfc818c.rlib -L native=/usr/local/opt/postgresql/lib`
error: custom derive attribute panicked
 --> src/schema.rs:1:1
  |
1 | infer_schema!("dotenv:DATABASE_URL");
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = help: message: assertion failed: !p.is_null()
  = note: this error originates in a macro outside of the current crate

error: failed to compile `diesel_demo_step_3_pg v0.1.0 (file:///Users/kir/Projects/opensource/diesel_start)`, intermediate artifacts can be found at `/Users/kir/Projects/opensource/diesel_start/target`

Caused by:
  Could not compile `diesel_demo_step_3_pg`.

Caused by:
  process didn't exit successfully: `rustc --crate-name diesel_demo_step_3_pg src/lib.rs --crate-type lib -C opt-level=3 -C metadata=a7e40dfea0887d49 -C extra-filename=-a7e40dfea0887d49 --out-dir /Users/kir/Projects/opensource/diesel_start/target/release/deps --emit=dep-info,link -L dependency=/Users/kir/Projects/opensource/diesel_start/target/release/deps --extern dotenv=/Users/kir/Projects/opensource/diesel_start/target/release/deps/libdotenv-c0ef68bcfc5b2489.rlib --extern diesel_codegen=/Users/kir/Projects/opensource/diesel_start/target/release/deps/libdiesel_codegen-eefe7fa2e56aaa65.dylib --extern diesel=/Users/kir/Projects/opensource/diesel_start/target/release/deps/libdiesel-82ac424c6bfc818c.rlib -L native=/usr/local/opt/postgresql/lib` (exit code: 101)

Not sure if RUST_BACKTRACE=1 makes the output different.

I also tried grepping target/release/deps for !p.is_null() assertion but there was nothing.

[sgrif]

What version of Rust are you running against? (rustc -vV)

[sgrif]

Assuming the answer is stable 1.15.1, I found the assertion. Very unsure what it means though... Can you give the output of diesel print-schema perhaps?

[kirs]

$ rustc -vV
rustc 1.15.1
binary: rustc
commit-hash: unknown
commit-date: unknown
host: x86_64-apple-darwin
release: 1.15.1
LLVM version: 3.9

$ diesel print-schema
table! {
    posts (id) {
        id -> Int4,
        title -> Varchar,
        body -> Text,
        published -> Bool,
    }
}

I'm curious about how did you find the assertion.

[sgrif]

I grepped the Rust source for assert!(!p.is_null. It's https://github.com/rust-lang/rust/blob/cfebdeaaccee40e060708d6b60c4abbe9edf72bb/src/libproc_macro/lib.rs#L156-L159 (which had no error message in 1.15.1).

I'd maybe give it a try on nightly. I'm unsure if this is an issue on our end or Rust's.

[kirs]

It works on nightly.

[kirs]

Thanks for your help! Should we close the issue?

[sgrif]

I suppose so. I wish I could reproduce the issue locally. :\