diff --git a/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/Lib.hs b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/Lib.hs
new file mode 100644
index 00000000000..f51af83e20a
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/Lib.hs
@@ -0,0 +1,4 @@
+module Lib (someFunc) where
+
+someFunc :: IO ()
+someFunc = putStrLn "someFunc"
diff --git a/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/WithProject.cabal b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/WithProject.cabal
new file mode 100644
index 00000000000..8ff172304b8
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/WithProject.cabal
@@ -0,0 +1,13 @@
+cabal-version:   3.0
+name:            WithProject
+version:         0.1.0.0
+build-type:      Simple
+
+common warnings
+    ghc-options: -Wall
+
+library
+    import:           warnings
+    exposed-modules:  Lib
+    build-depends:    base
+    default-language: Haskell2010
diff --git a/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/cabal.project b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/cabal.project
new file mode 100644
index 00000000000..3f3d6b6e7ae
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/cabal.project
@@ -0,0 +1,4 @@
+packages: ./
+
+package WithProject
+    ghc-options: -haddock
diff --git a/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/with-project.out b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/with-project.out
new file mode 100644
index 00000000000..b600e6ad2e4
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/with-project.out
@@ -0,0 +1,10 @@
+# cabal build
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - WithProject-0.1.0.0 (lib) (first run)
+Configuring library for WithProject-0.1.0.0...
+Preprocessing library for WithProject-0.1.0.0...
+Building library for WithProject-0.1.0.0...
+# show-build-info WithProject lib
+{"cabal-lib-version":"<CABALVER>","compiler":{"flavour":"ghc","compiler-id":"ghc-<GHCVER>","path":"<GHCPATH>"},"components":[{"type":"lib","name":"lib","unit-id":"WithProject-0.1.0.0-inplace","compiler-args":["-fbuilding-cabal-package","-O","-outputdir","with-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build","-odir","with-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build","-hidir","with-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build","-stubdir","with-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build","-i","-i.","-iwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build","-iwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build/autogen","-iwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build/global-autogen","-Iwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build/autogen","-Iwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build/global-autogen","-Iwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build","-optP-include","-optPwith-project.dist/work/./dist/build/<ARCH>/ghc-<GHCVER>/WithProject-0.1.0.0/build/autogen/cabal_macros.h","-this-unit-id","WithProject-0.1.0.0-inplace","-hide-all-packages","-Wmissing-home-modules","-no-user-package-db","-package-db","<ROOT>/with-project.dist/home/.cabal/store/ghc-<GHCVER>/package.db","-package-db","<ROOT>/with-project.dist/work/./dist/packagedb/ghc-<GHCVER>","-package-id","<PACKAGEDEP>","-XHaskell2010","-Wall"],"modules":["Lib"],"src-files":[],"hs-src-dirs":["."],"src-dir":"<ROOT>/","cabal-file":"WithProject.cabal"}]}
diff --git a/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/with-project.test.hs b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/with-project.test.hs
new file mode 100644
index 00000000000..442674e756e
--- /dev/null
+++ b/cabal-testsuite/PackageTests/ShowBuildInfo/WithProject/with-project.test.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE OverloadedStrings #-}
+import           Test.Cabal.Prelude
+import           Test.Cabal.DecodeShowBuildInfo
+
+main = cabalTest $ do
+  runShowBuildInfo ["lib:WithProject"]
+  withPlan $ do
+    recordBuildInfo "WithProject" mainLib
+    assertComponent "WithProject" mainLib defCompAssertion
+      { compilerArgsPred = ("-Wall" `elem`) -- added by 'WithProject.cabal'
+      , modules = ["Lib"]
+      , sourceDirs = ["."]
+      }
+
+    -- See #9927
+    assertComponent "WithProject" mainLib defCompAssertion
+      { compilerArgsPred = ("-haddock" `notElem`) -- added by 'cabal.project', but not present
+      , modules = ["Lib"]
+      , sourceDirs = ["."]
+      }
+