diff --git a/csharp/ql/integration-tests/posix-only/diag_autobuild_script/build.sh b/csharp/ql/integration-tests/posix-only/diag_autobuild_script/build.sh
new file mode 100755
index 00000000000..2bb8d868bd0
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_autobuild_script/build.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exit 1
diff --git a/csharp/ql/integration-tests/posix-only/diag_autobuild_script/diagnostics.expected b/csharp/ql/integration-tests/posix-only/diag_autobuild_script/diagnostics.expected
new file mode 100644
index 00000000000..69bcf765eee
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_autobuild_script/diagnostics.expected
@@ -0,0 +1,32 @@
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "markdownMessage": "CodeQL attempted to build your project using a script located at `build.sh`, which failed. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/script-failure",
+    "name": "Unable to build project using build script"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "plaintextMessage": "CodeQL could not find any project or solution files in your repository. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/no-projects-or-solutions",
+    "name": "No project or solutions files found"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
diff --git a/csharp/ql/integration-tests/posix-only/diag_autobuild_script/test.py b/csharp/ql/integration-tests/posix-only/diag_autobuild_script/test.py
new file mode 100644
index 00000000000..62c4d3934a4
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_autobuild_script/test.py
@@ -0,0 +1,5 @@
+from create_database_utils import *
+from diagnostics_test_utils import *
+
+run_codeql_database_create([], db=None, lang="csharp", runFunction=runUnsuccessfully)
+check_diagnostics()
diff --git a/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/build.sh b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/build.sh
new file mode 100755
index 00000000000..2bb8d868bd0
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/build.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exit 1
diff --git a/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/diagnostics.expected b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/diagnostics.expected
new file mode 100644
index 00000000000..253ef636fd1
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/diagnostics.expected
@@ -0,0 +1,32 @@
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "markdownMessage": "CodeQL found multiple potential build scripts for your project and attempted to run `build.sh`, which failed. This may not be the right build script for your project. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/multiple-build-scripts",
+    "name": "There are multiple potential build scripts"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "plaintextMessage": "CodeQL could not find any project or solution files in your repository. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/no-projects-or-solutions",
+    "name": "No project or solutions files found"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
diff --git a/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/scripts/build.sh b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/scripts/build.sh
new file mode 100755
index 00000000000..2bb8d868bd0
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/scripts/build.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exit 1
diff --git a/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/test.py b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/test.py
new file mode 100644
index 00000000000..62c4d3934a4
--- /dev/null
+++ b/csharp/ql/integration-tests/posix-only/diag_multiple_scripts/test.py
@@ -0,0 +1,5 @@
+from create_database_utils import *
+from diagnostics_test_utils import *
+
+run_codeql_database_create([], db=None, lang="csharp", runFunction=runUnsuccessfully)
+check_diagnostics()
diff --git a/csharp/ql/integration-tests/windows-only/diag_autobuild_script/build.bat b/csharp/ql/integration-tests/windows-only/diag_autobuild_script/build.bat
new file mode 100644
index 00000000000..8f7ce95c0eb
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_autobuild_script/build.bat
@@ -0,0 +1 @@
+exit /b 1
diff --git a/csharp/ql/integration-tests/windows-only/diag_autobuild_script/diagnostics.expected b/csharp/ql/integration-tests/windows-only/diag_autobuild_script/diagnostics.expected
new file mode 100644
index 00000000000..a5096fcbf7b
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_autobuild_script/diagnostics.expected
@@ -0,0 +1,32 @@
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "markdownMessage": "CodeQL attempted to build your project using a script located at `build.bat`, which failed. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/script-failure",
+    "name": "Unable to build project using build script"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "plaintextMessage": "CodeQL could not find any project or solution files in your repository. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/no-projects-or-solutions",
+    "name": "No project or solutions files found"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
diff --git a/csharp/ql/integration-tests/windows-only/diag_autobuild_script/test.py b/csharp/ql/integration-tests/windows-only/diag_autobuild_script/test.py
new file mode 100644
index 00000000000..62c4d3934a4
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_autobuild_script/test.py
@@ -0,0 +1,5 @@
+from create_database_utils import *
+from diagnostics_test_utils import *
+
+run_codeql_database_create([], db=None, lang="csharp", runFunction=runUnsuccessfully)
+check_diagnostics()
diff --git a/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/build.bat b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/build.bat
new file mode 100644
index 00000000000..8f7ce95c0eb
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/build.bat
@@ -0,0 +1 @@
+exit /b 1
diff --git a/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/diagnostics.expected b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/diagnostics.expected
new file mode 100644
index 00000000000..91815aa78af
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/diagnostics.expected
@@ -0,0 +1,32 @@
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "markdownMessage": "CodeQL found multiple potential build scripts for your project and attempted to run `build.bat`, which failed. This may not be the right build script for your project. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/multiple-build-scripts",
+    "name": "There are multiple potential build scripts"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
+{
+  "attributes": {},
+  "helpLinks": [],
+  "internal": false,
+  "location": {},
+  "plaintextMessage": "CodeQL could not find any project or solution files in your repository. Set up a [manual build command](https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-the-codeql-workflow-for-compiled-languages).",
+  "severity": "error",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/no-projects-or-solutions",
+    "name": "No project or solutions files found"
+  },
+  "visibility": {
+    "statusPage": true
+  }
+}
diff --git a/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/scripts/build.bat b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/scripts/build.bat
new file mode 100644
index 00000000000..8f7ce95c0eb
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/scripts/build.bat
@@ -0,0 +1 @@
+exit /b 1
diff --git a/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/test.py b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/test.py
new file mode 100644
index 00000000000..62c4d3934a4
--- /dev/null
+++ b/csharp/ql/integration-tests/windows-only/diag_multiple_scripts/test.py
@@ -0,0 +1,5 @@
+from create_database_utils import *
+from diagnostics_test_utils import *
+
+run_codeql_database_create([], db=None, lang="csharp", runFunction=runUnsuccessfully)
+check_diagnostics()