diff --git a/cabal-install/src/Distribution/Client/ParseUtils.hs b/cabal-install/src/Distribution/Client/ParseUtils.hs
index 18062b7428f..96c702a2970 100644
--- a/cabal-install/src/Distribution/Client/ParseUtils.hs
+++ b/cabal-install/src/Distribution/Client/ParseUtils.hs
@@ -1,6 +1,8 @@
{-# LANGUAGE ExistentialQuantification #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
-----------------------------------------------------------------------------
@@ -53,6 +55,7 @@ import Distribution.Deprecated.ParseUtils
( Field (..)
, FieldDescr (..)
, LineNo
+ , PError (..)
, ParseResult (..)
, liftField
, lineNo
@@ -292,13 +295,16 @@ parseFieldsAndSections fieldDescrs sectionDescrs fgSectionDescrs =
setField a (F line name value) =
case Map.lookup name fieldMap of
Just (FieldDescr _ _ set) -> set line value a
- Nothing -> do
- warning $
- "Unrecognized field '"
- ++ name
- ++ "' on line "
- ++ show line
- return a
+ Nothing ->
+ case Left <$> Map.lookup name sectionMap <|> Right <$> Map.lookup name fgSectionMap of
+ Just _ -> ParseFailed $ FieldShouldBeStanza name line
+ Nothing -> do
+ warning $
+ "Unrecognized field '"
+ ++ name
+ ++ "' on line "
+ ++ show line
+ return a
setField a (Section line name param fields) =
case Left <$> Map.lookup name sectionMap <|> Right <$> Map.lookup name fgSectionMap of
Just (Left (SectionDescr _ fieldDescrs' sectionDescrs' _ set sectionEmpty)) -> do
diff --git a/cabal-install/src/Distribution/Deprecated/ParseUtils.hs b/cabal-install/src/Distribution/Deprecated/ParseUtils.hs
index e1d389ac9aa..4743213fde9 100644
--- a/cabal-install/src/Distribution/Deprecated/ParseUtils.hs
+++ b/cabal-install/src/Distribution/Deprecated/ParseUtils.hs
@@ -91,6 +91,7 @@ data PError
= AmbiguousParse String LineNo
| NoParse String LineNo
| TabsError LineNo
+ | FieldShouldBeStanza String LineNo
| FromString String (Maybe LineNo)
deriving (Eq, Show)
@@ -186,6 +187,10 @@ locatedErrorMsg (NoParse f n) =
, "Parse of field '" ++ f ++ "' failed."
)
locatedErrorMsg (TabsError n) = (Just n, "Tab used as indentation.")
+locatedErrorMsg (FieldShouldBeStanza name lineNumber) =
+ ( Just lineNumber
+ , "'" ++ name ++ "' is a stanza, not a field. Remove the trailing ':' to parse a stanza."
+ )
locatedErrorMsg (FromString s n) = (n, s)
syntaxError :: LineNo -> String -> ParseResult a
diff --git a/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.out b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.out
new file mode 100644
index 00000000000..60680b86db3
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.out
@@ -0,0 +1,4 @@
+# cabal build
+Error: [Cabal-7090]
+Error parsing project file <ROOT>/cabal.project:4:
+'source-repository-package' is a stanza, not a field. Remove the trailing ':' to parse a stanza.
diff --git a/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.project b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.project
new file mode 100644
index 00000000000..518ac39f5fb
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.project
@@ -0,0 +1,6 @@
+packages: .
+
+-- This is an error; a trailing `:` is syntax for a field, not a stanza!
+source-repository-package:
+ type: git
+ location: https://github.com/haskell-hvr/Only
diff --git a/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.test.hs b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.test.hs
new file mode 100644
index 00000000000..39636819157
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/cabal.test.hs
@@ -0,0 +1,6 @@
+import Test.Cabal.Prelude
+
+main = cabalTest $ do
+ result <- fails $ cabal' "build" []
+ assertOutputContains "Error parsing project file" result
+ assertOutputContains "'source-repository-package' is a stanza, not a field." result
diff --git a/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/src/MyLib.hs b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/src/MyLib.hs
new file mode 100644
index 00000000000..e657c4403f6
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/src/MyLib.hs
@@ -0,0 +1,4 @@
+module MyLib (someFunc) where
+
+someFunc :: IO ()
+someFunc = putStrLn "someFunc"
diff --git a/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/test.cabal b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/test.cabal
new file mode 100644
index 00000000000..86374a457c7
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ProjectConfig/FieldStanzaConfusion/test.cabal
@@ -0,0 +1,13 @@
+cabal-version: 3.0
+name: test
+version: 0.1.0.0
+license: NONE
+author: rbt@sent.as
+maintainer: Rebecca Turner
+build-type: Simple
+
+library
+ exposed-modules: MyLib
+ build-depends: base
+ hs-source-dirs: src
+ default-language: Haskell2010
diff --git a/changelog.d/pr-10525 b/changelog.d/pr-10525
new file mode 100644
index 00000000000..7235d0bec74
--- /dev/null
+++ b/changelog.d/pr-10525
@@ -0,0 +1,34 @@
+---
+synopsis: "A trailing colon after a stanza name in `cabal.project` is now an error"
+packages: [cabal-install]
+prs: 10525
+---
+
+It is now a hard error to use a trailing colon after a stanza name in
+`cabal.project` or `*.cabal` files:
+
+```
+packages: .
+
+source-repository-package:
+ type: git
+ location: https://github.com/haskell/cabal
+ tag: f34aba976a60940295f41b6649674e9568893894
+```
+
+```
+$ cabal build
+Error parsing project file cabal.project:3:
+'source-repository-package' is a stanza, not a field. Remove the trailing ':' to parse a stanza.
+```
+
+Previously, the warning message was easily ignored and somewhat misleading, as
+the difference between a stanza and a field is not immediately obvious to
+Haskellers used to config languages like JSON and YAML (which don't distinguish
+between fields which have string or list values and stanzas which have nested
+fields):
+
+```
+Warning: cabal.project: Unrecognized field
+'source-repository-package' on line 3
+```