Remove the fallback provider

Change-Id: Idbb8b86d2630cd1852fca6792e7795a8a8df490e
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

23 files changed, 27 insertions, 184 deletions

diff --git a/doc/appendix/json-api.qdoc b/doc/appendix/json-api.qdoc
index 02ec6aef3..7b093bc4e 100644
--- a/doc/appendix/json-api.qdoc
+++ b/doc/appendix/json-api.qdoc
@@ -126,7 +126,6 @@
     \row    \li dry-run                      \li bool                \li no
     \row    \li environment                  \li \l Environment      \li no
     \row    \li error-handling-mode          \li string              \li no
-    \row    \li fallback-provider-enabled    \li bool                \li no
     \row    \li force-probe-execution        \li bool                \li no
     \row    \li log-time                     \li bool                \li no
     \row    \li log-level                    \li \l LogLevel         \li no
diff --git a/doc/reference/cli/builtin/cli-build.qdoc b/doc/reference/cli/builtin/cli-build.qdoc
index 683b1ebb8..8547a78d2 100644
--- a/doc/reference/cli/builtin/cli-build.qdoc
+++ b/doc/reference/cli/builtin/cli-build.qdoc
@@ -78,8 +78,6 @@
     \include cli-options.qdocinc products-specified
     \include cli-options.qdocinc settings-dir
     \include cli-options.qdocinc show-progress
-    \target no-fallback-module-provider
-    \include cli-options.qdocinc no-fallback-module-provider
     \include cli-options.qdocinc wait-lock
 
     \section1 Parameters
diff --git a/doc/reference/cli/builtin/cli-resolve.qdoc b/doc/reference/cli/builtin/cli-resolve.qdoc
index 4569980bd..99f1658ea 100644
--- a/doc/reference/cli/builtin/cli-resolve.qdoc
+++ b/doc/reference/cli/builtin/cli-resolve.qdoc
@@ -55,7 +55,6 @@
     \include cli-options.qdocinc more-verbose
     \include cli-options.qdocinc settings-dir
     \include cli-options.qdocinc show-progress
-    \include cli-options.qdocinc no-fallback-module-provider
     \include cli-options.qdocinc deprecation-warnings
 
     \section1 Parameters
diff --git a/src/app/qbs/commandlinefrontend.cpp b/src/app/qbs/commandlinefrontend.cpp
index 4248f55a7..4a4781207 100644
--- a/src/app/qbs/commandlinefrontend.cpp
+++ b/src/app/qbs/commandlinefrontend.cpp
@@ -152,7 +152,6 @@ void CommandLineFrontend::start()
         params.setDryRun(m_parser.dryRun());
         params.setForceProbeExecution(m_parser.forceProbesExecution());
         params.setWaitLockBuildGraph(m_parser.waitLockBuildGraph());
-        params.setFallbackProviderEnabled(!m_parser.disableFallbackProvider());
         params.setLogElapsedTime(m_parser.logTime());
         params.setSettingsDirectory(m_settings->baseDirectory());
         params.setOverrideBuildGraphData(m_parser.command() == ResolveCommandType);
diff --git a/src/app/qbs/parser/commandlineoption.cpp b/src/app/qbs/parser/commandlineoption.cpp
index 389b304f0..7572b4e66 100644
--- a/src/app/qbs/parser/commandlineoption.cpp
+++ b/src/app/qbs/parser/commandlineoption.cpp
@@ -710,17 +710,6 @@ QString WaitLockOption::longRepresentation() const
     return QStringLiteral("--wait-lock");
 }
 
-QString DisableFallbackProviderOption::description(CommandType) const
-{
-    return Tr::tr("%1\n\tDo not fall back to pkg-config if a dependency is not found.\n")
-            .arg(longRepresentation());
-}
-
-QString DisableFallbackProviderOption::longRepresentation() const
-{
-    return QStringLiteral("--no-fallback-module-provider");
-}
-
 QString RunEnvConfigOption::description(CommandType command) const
 {
     Q_UNUSED(command);
diff --git a/src/app/qbs/parser/commandlineoption.h b/src/app/qbs/parser/commandlineoption.h
index d51d5f765..b12d96b2d 100644
--- a/src/app/qbs/parser/commandlineoption.h
+++ b/src/app/qbs/parser/commandlineoption.h
@@ -76,7 +76,6 @@ public:
         GeneratorOptionType,
         WaitLockOptionType,
         RunEnvConfigOptionType,
-        DisableFallbackProviderType,
         DeprecationWarningsOptionType,
     };
 
@@ -431,14 +430,6 @@ public:
     QString longRepresentation() const override;
 };
 
-class DisableFallbackProviderOption : public OnOffOption
-{
-public:
-    QString description(CommandType command) const override;
-    QString shortRepresentation() const override { return {}; }
-    QString longRepresentation() const override;
-};
-
 } // namespace qbs
 
 #endif // QBS_COMMANDLINEOPTION_H
diff --git a/src/app/qbs/parser/commandlineoptionpool.cpp b/src/app/qbs/parser/commandlineoptionpool.cpp
index 3908f262c..692c9c737 100644
--- a/src/app/qbs/parser/commandlineoptionpool.cpp
+++ b/src/app/qbs/parser/commandlineoptionpool.cpp
@@ -128,9 +128,6 @@ CommandLineOption *CommandLineOptionPool::getOption(CommandLineOption::Type type
         case CommandLineOption::WaitLockOptionType:
             option = new WaitLockOption;
             break;
-        case CommandLineOption::DisableFallbackProviderType:
-            option = new DisableFallbackProviderOption;
-            break;
         case CommandLineOption::RunEnvConfigOptionType:
             option = new RunEnvConfigOption;
             break;
@@ -279,12 +276,6 @@ WaitLockOption *CommandLineOptionPool::waitLockOption() const
     return static_cast<WaitLockOption *>(getOption(CommandLineOption::WaitLockOptionType));
 }
 
-DisableFallbackProviderOption *CommandLineOptionPool::disableFallbackProviderOption() const
-{
-    return static_cast<DisableFallbackProviderOption *>(
-                getOption(CommandLineOption::DisableFallbackProviderType));
-}
-
 RunEnvConfigOption *CommandLineOptionPool::runEnvConfigOption() const
 {
     return static_cast<RunEnvConfigOption *>(getOption(CommandLineOption::RunEnvConfigOptionType));
diff --git a/src/app/qbs/parser/commandlineoptionpool.h b/src/app/qbs/parser/commandlineoptionpool.h
index 5f3c1d87c..022e9fd09 100644
--- a/src/app/qbs/parser/commandlineoptionpool.h
+++ b/src/app/qbs/parser/commandlineoptionpool.h
@@ -77,7 +77,6 @@ public:
     RespectProjectJobLimitsOption *respectProjectJobLimitsOption() const;
     GeneratorOption *generatorOption() const;
     WaitLockOption *waitLockOption() const;
-    DisableFallbackProviderOption *disableFallbackProviderOption() const;
     RunEnvConfigOption *runEnvConfigOption() const;
     DeprecationWarningsOption *deprecationWarningsOption() const;
 
diff --git a/src/app/qbs/parser/commandlineparser.cpp b/src/app/qbs/parser/commandlineparser.cpp
index 7fbfa28f1..c548cf2b5 100644
--- a/src/app/qbs/parser/commandlineparser.cpp
+++ b/src/app/qbs/parser/commandlineparser.cpp
@@ -231,11 +231,6 @@ bool CommandLineParser::waitLockBuildGraph() const
     return d->optionPool.waitLockOption()->enabled();
 }
 
-bool CommandLineParser::disableFallbackProvider() const
-{
-    return d->optionPool.disableFallbackProviderOption()->enabled();
-}
-
 bool CommandLineParser::logTime() const
 {
     return d->logTime;
diff --git a/src/app/qbs/parser/commandlineparser.h b/src/app/qbs/parser/commandlineparser.h
index 4ce7756ef..4df8829a2 100644
--- a/src/app/qbs/parser/commandlineparser.h
+++ b/src/app/qbs/parser/commandlineparser.h
@@ -81,7 +81,6 @@ public:
     bool dryRun() const;
     bool forceProbesExecution() const;
     bool waitLockBuildGraph() const;
-    bool disableFallbackProvider() const;
     bool logTime() const;
     bool withNonDefaultProducts() const;
     bool buildBeforeInstalling() const;
diff --git a/src/app/qbs/parser/parsercommand.cpp b/src/app/qbs/parser/parsercommand.cpp
index f11a7b6ac..84eef9774 100644
--- a/src/app/qbs/parser/parsercommand.cpp
+++ b/src/app/qbs/parser/parsercommand.cpp
@@ -209,8 +209,7 @@ static QList<CommandLineOption::Type> resolveOptions()
             CommandLineOption::ForceProbesOptionType,
             CommandLineOption::LogTimeOptionType,
             CommandLineOption::DeprecationWarningsOptionType,
-            CommandLineOption::JobsOptionType,
-            CommandLineOption::DisableFallbackProviderType};
+            CommandLineOption::JobsOptionType};
 }
 
 QList<CommandLineOption::Type> ResolveCommand::supportedOptions() const
diff --git a/src/lib/corelib/language/builtindeclarations.cpp b/src/lib/corelib/language/builtindeclarations.cpp
index 491b005e8..24e8f1cfb 100644
--- a/src/lib/corelib/language/builtindeclarations.cpp
+++ b/src/lib/corelib/language/builtindeclarations.cpp
@@ -250,14 +250,6 @@ void BuiltinDeclarations::addDependsItem()
     item << PropertyDeclaration(StringConstants::multiplexConfigurationIdsProperty(),
                                 PropertyDeclaration::StringList, QString(),
                                 PropertyDeclaration::ReadOnlyFlag);
-    PropertyDeclaration fallbackProp(
-        StringConstants::enableFallbackProperty(),
-        PropertyDeclaration::Boolean,
-        StringConstants::falseValue());
-    fallbackProp.setDeprecationInfo(DeprecationInfo(
-        Version(2, 4),
-        Tr::tr("The fallback provider has been deprecated. Use qbspkgconfig instead.")));
-    item << fallbackProp;
     insert(item);
 }
 
diff --git a/src/lib/corelib/loader/dependenciesresolver.cpp b/src/lib/corelib/loader/dependenciesresolver.cpp
index 479318e73..b97580f27 100644
--- a/src/lib/corelib/loader/dependenciesresolver.cpp
+++ b/src/lib/corelib/loader/dependenciesresolver.cpp
@@ -89,7 +89,6 @@ public:
     VersionRange versionRange;
     QVariantMap parameters;
     bool limitToSubProject = false;
-    FallbackMode fallbackMode = FallbackMode::Enabled;
     bool requiredLocally = true;
     bool requiredGlobally = true;
 };
@@ -123,7 +122,6 @@ public:
     VersionRange versionRange;
     QVariantMap parameters;
     bool limitToSubProject = false;
-    FallbackMode fallbackMode = FallbackMode::Enabled;
     bool requiredLocally = true;
     bool requiredGlobally = true;
     bool checkProduct = true;
@@ -592,8 +590,8 @@ Item *DependenciesResolver::findMatchingModule(
         return nullptr;
     }
 
-    if (Item *moduleItem = searchAndLoadModuleFile(m_loaderState, m_product, dependency.location(),
-                                                   dependency.name, dependency.fallbackMode)) {
+    if (Item *moduleItem = searchAndLoadModuleFile(
+            m_loaderState, m_product, dependency.location(), dependency.name)) {
         QBS_CHECK(moduleItem->type() == ItemType::Module);
         Item * const proto = moduleItem;
         ModuleItemLocker locker(*moduleItem);
@@ -849,11 +847,6 @@ std::optional<EvaluatedDependsItem> DependenciesResolver::evaluateDependsItem(It
                         item->location());
     }
 
-    const FallbackMode fallbackMode
-            = m_loaderState.parameters().fallbackProviderEnabled()
-                  && evaluator.boolValue(item, StringConstants::enableFallbackProperty())
-              ? FallbackMode::Enabled : FallbackMode::Disabled;
-
     bool profilesPropertyWasSet = false;
     std::optional<QStringList> profiles;
     bool required = true;
@@ -882,7 +875,7 @@ std::optional<EvaluatedDependsItem> DependenciesResolver::evaluateDependsItem(It
     return EvaluatedDependsItem{
         item, QualifiedId::fromString(name), submodules, productTypeTags,
         multiplexIds, profiles, {minVersion, maxVersion}, parameters, limitToSubProject,
-        fallbackMode, required};
+        required};
 }
 
 // Potentially multiplexes a dependency along Depends.productTypes, Depends.subModules and
@@ -1038,12 +1031,11 @@ FullyResolvedDependsItem::FullyResolvedDependsItem(
     ProductContext *product, const EvaluatedDependsItem &dependency)
     : product(product), item(dependency.item), name(product->name),
     versionRange(dependency.versionRange), parameters(dependency.parameters),
-    fallbackMode(FallbackMode::Disabled), checkProduct(false) {}
+    checkProduct(false) {}
 
 FullyResolvedDependsItem FullyResolvedDependsItem::makeBaseDependency()
 {
     FullyResolvedDependsItem item;
-    item.fallbackMode = FallbackMode::Disabled;
     item.name = StringConstants::qbsModule();
     return item;
 }
@@ -1055,7 +1047,6 @@ FullyResolvedDependsItem::FullyResolvedDependsItem(
       versionRange(dependency.versionRange),
       parameters(dependency.parameters),
       limitToSubProject(dependency.limitToSubProject),
-      fallbackMode(dependency.fallbackMode),
       requiredLocally(dependency.requiredLocally),
       requiredGlobally(dependency.requiredGlobally) {}
 
diff --git a/src/lib/corelib/loader/loaderutils.h b/src/lib/corelib/loader/loaderutils.h
index 3f967ba08..4a4aadfb8 100644
--- a/src/lib/corelib/loader/loaderutils.h
+++ b/src/lib/corelib/loader/loaderutils.h
@@ -83,7 +83,6 @@ class ScriptEngine;
 using ModulePropertiesPerGroup = std::unordered_map<const Item *, QualifiedIdSet>;
 using FileLocations = QHash<std::pair<QString, QString>, CodeLocation>;
 
-enum class FallbackMode { Enabled, Disabled };
 enum class Deferral { Allowed, NotAllowed };
 enum class ProductDependency { None, Single, Bulk };
 
diff --git a/src/lib/corelib/loader/moduleloader.cpp b/src/lib/corelib/loader/moduleloader.cpp
index 80aa3f17c..80956377c 100644
--- a/src/lib/corelib/loader/moduleloader.cpp
+++ b/src/lib/corelib/loader/moduleloader.cpp
@@ -68,12 +68,15 @@ namespace qbs::Internal {
 class ModuleLoader
 {
 public:
-    ModuleLoader(LoaderState &loaderState, ProductContext &product,
-                 const CodeLocation &dependsItemLocation, const QualifiedId &moduleName,
-                 FallbackMode fallbackMode)
-        : m_loaderState(loaderState), m_product(product),
-          m_dependsItemLocation(dependsItemLocation), m_moduleName(moduleName),
-          m_fallbackMode(fallbackMode)
+    ModuleLoader(
+        LoaderState &loaderState,
+        ProductContext &product,
+        const CodeLocation &dependsItemLocation,
+        const QualifiedId &moduleName)
+        : m_loaderState(loaderState)
+        , m_product(product)
+        , m_dependsItemLocation(dependsItemLocation)
+        , m_moduleName(moduleName)
     {}
 
     Item *load();
@@ -92,7 +95,6 @@ private:
     ProductContext &m_product;
     const CodeLocation &m_dependsItemLocation;
     const QualifiedId &m_moduleName;
-    const FallbackMode m_fallbackMode;
 };
 
 struct PrioritizedItem
@@ -142,11 +144,13 @@ static Item *chooseModuleCandidate(const std::vector<PrioritizedItem> &candidate
     return maxIt->item;
 }
 
-Item *searchAndLoadModuleFile(LoaderState &loaderState, ProductContext &product,
-        const CodeLocation &dependsItemLocation, const QualifiedId &moduleName,
-        FallbackMode fallbackMode)
+Item *searchAndLoadModuleFile(
+    LoaderState &loaderState,
+    ProductContext &product,
+    const CodeLocation &dependsItemLocation,
+    const QualifiedId &moduleName)
 {
-    return ModuleLoader(loaderState, product, dependsItemLocation, moduleName, fallbackMode).load();
+    return ModuleLoader(loaderState, product, dependsItemLocation, moduleName).load();
 }
 
 Item *ModuleLoader::load()
@@ -158,7 +162,7 @@ Item *ModuleLoader::load()
         AccumulatingTimer providersTimer(m_loaderState.parameters().logElapsedTime()
                                          ? &m_product.timingData.moduleProviders : nullptr);
         auto result = ModuleProviderLoader(m_loaderState).executeModuleProviders(
-                    m_product, m_dependsItemLocation, m_moduleName, m_fallbackMode);
+                    m_product, m_dependsItemLocation, m_moduleName);
         if (result.searchPaths) {
             qCDebug(lcModuleLoader) << "Re-checking for module" << m_moduleName.toString()
                                     << "with newly added search paths from module provider";
diff --git a/src/lib/corelib/loader/moduleloader.h b/src/lib/corelib/loader/moduleloader.h
index 60567e60e..e9ae214b8 100644
--- a/src/lib/corelib/loader/moduleloader.h
+++ b/src/lib/corelib/loader/moduleloader.h
@@ -42,7 +42,6 @@
 namespace qbs {
 class CodeLocation;
 namespace Internal {
-enum class FallbackMode;
 class Item;
 class LoaderState;
 class ProductContext;
@@ -50,7 +49,7 @@ class QualifiedId;
 
 Item *searchAndLoadModuleFile(LoaderState &loaderState, ProductContext &product,
                               const CodeLocation &dependsItemLocation,
-                              const QualifiedId &moduleName, FallbackMode fallbackMode);
+                              const QualifiedId &moduleName);
 
 } // namespace Internal
 } // namespace qbs
diff --git a/src/lib/corelib/loader/moduleproviderloader.cpp b/src/lib/corelib/loader/moduleproviderloader.cpp
index a9f5eb26f..a8b99ca20 100644
--- a/src/lib/corelib/loader/moduleproviderloader.cpp
+++ b/src/lib/corelib/loader/moduleproviderloader.cpp
@@ -78,8 +78,7 @@ ModuleProviderLoader::ModuleProviderLoader(LoaderState &loaderState)
 ModuleProviderLoader::ModuleProviderResult ModuleProviderLoader::executeModuleProviders(
         ProductContext &productContext,
         const CodeLocation &dependsItemLocation,
-        const QualifiedId &moduleName,
-        FallbackMode fallbackMode)
+        const QualifiedId &moduleName)
 {
     ModuleProviderLoader::ModuleProviderResult result;
     try {
@@ -98,18 +97,6 @@ ModuleProviderLoader::ModuleProviderResult ModuleProviderLoader::executeModulePr
         }
         result = executeModuleProvidersHelper(
             productContext, dependsItemLocation, moduleName, providersToRun);
-
-        if (fallbackMode == FallbackMode::Enabled
-                && !result.providerFound
-                && !providerNames) {
-                qCDebug(lcModuleLoader) << "Specific module provider not found for"
-                                    << moduleName.toString()  << ", setting up fallback.";
-            result = executeModuleProvidersHelper(
-                    productContext,
-                    dependsItemLocation,
-                    moduleName,
-                    {{moduleName, ModuleProviderLookup::Fallback}});
-        }
     } catch (const ErrorInfo &error) {
         auto ei = error;
         ei.prepend(
@@ -291,9 +278,6 @@ QString ModuleProviderLoader::findModuleProviderFile(
                 fullPath = FileInfo::resolvePath(fullPath, component);
             fullPath = FileInfo::resolvePath(fullPath, QStringLiteral("provider.qbs"));
             break;
-        case ModuleProviderLookup::Fallback:
-            fullPath = FileInfo::resolvePath(fullPath, QStringLiteral("__fallback/provider.qbs"));
-            break;
         }
         if (!FileInfo::exists(fullPath)) {
             qCDebug(lcModuleLoader) << "No module provider found at" << fullPath;
diff --git a/src/lib/corelib/loader/moduleproviderloader.h b/src/lib/corelib/loader/moduleproviderloader.h
index 0b1145db5..4fe94217b 100644
--- a/src/lib/corelib/loader/moduleproviderloader.h
+++ b/src/lib/corelib/loader/moduleproviderloader.h
@@ -69,11 +69,10 @@ public:
     ModuleProviderResult executeModuleProviders(
             ProductContext &productContext,
             const CodeLocation &dependsItemLocation,
-            const QualifiedId &moduleName,
-            FallbackMode fallbackMode);
+            const QualifiedId &moduleName);
 
 private:
-    enum class ModuleProviderLookup { Scoped, Named, Fallback };
+    enum class ModuleProviderLookup { Scoped, Named };
     struct Provider {
         QualifiedId name;
         ModuleProviderLookup lookup;
diff --git a/src/lib/corelib/tools/setupprojectparameters.cpp b/src/lib/corelib/tools/setupprojectparameters.cpp
index 185323c09..e9212c165 100644
--- a/src/lib/corelib/tools/setupprojectparameters.cpp
+++ b/src/lib/corelib/tools/setupprojectparameters.cpp
@@ -99,7 +99,6 @@ public:
     bool logElapsedTime;
     bool forceProbeExecution;
     bool waitLockBuildGraph;
-    bool fallbackProviderEnabled = true;
     SetupProjectParameters::RestoreBehavior restoreBehavior;
     ErrorHandlingMode propertyCheckingMode;
     ErrorHandlingMode productErrorMode;
@@ -166,7 +165,6 @@ SetupProjectParameters SetupProjectParameters::fromJson(const QJsonObject &data)
     setValueFromJson(params.d->logElapsedTime, data, "log-time");
     setValueFromJson(params.d->forceProbeExecution, data, "force-probe-execution");
     setValueFromJson(params.d->waitLockBuildGraph, data, "wait-lock-build-graph");
-    setValueFromJson(params.d->fallbackProviderEnabled, data, "fallback-provider-enabled");
     setValueFromJson(params.d->environment, data, "environment");
     setValueFromJson(params.d->restoreBehavior, data, "restore-behavior");
     setValueFromJson(params.d->propertyCheckingMode, data, "error-handling-mode");
@@ -623,22 +621,6 @@ void SetupProjectParameters::setWaitLockBuildGraph(bool wait)
 }
 
 /*!
- * \brief Returns true if qbs should fall back to pkg-config if a dependency is not found.
- */
-bool SetupProjectParameters::fallbackProviderEnabled() const
-{
-    return d->fallbackProviderEnabled;
-}
-
-/*!
- * Controls whether to fall back to pkg-config if a dependency is not found.
- */
-void SetupProjectParameters::setFallbackProviderEnabled(bool enable)
-{
-    d->fallbackProviderEnabled = enable;
-}
-
-/*!
  * \brief Gets the environment used while resolving the project.
  */
 QProcessEnvironment SetupProjectParameters::environment() const
diff --git a/src/lib/corelib/tools/setupprojectparameters.h b/src/lib/corelib/tools/setupprojectparameters.h
index 76b038752..5cd9700a9 100644
--- a/src/lib/corelib/tools/setupprojectparameters.h
+++ b/src/lib/corelib/tools/setupprojectparameters.h
@@ -132,9 +132,6 @@ public:
     bool waitLockBuildGraph() const;
     void setWaitLockBuildGraph(bool wait);
 
-    bool fallbackProviderEnabled() const;
-    void setFallbackProviderEnabled(bool enable);
-
     QProcessEnvironment environment() const;
     void setEnvironment(const QProcessEnvironment &env);
     QProcessEnvironment adjustedEnvironment() const;
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index 917d7436c..c62fdbca0 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -6058,12 +6058,9 @@ void TestBlackbox::protobuf_data()
     QTest::addColumn<QStringList>("properties");
     QTest::addColumn<bool>("hasModules");
     QTest::addColumn<bool>("successExpected");
-    QTest::newRow("cpp-fallback") << QString("addressbook_cpp.qbs") << QStringList() << true << true;
     QTest::newRow("cpp-pkgconfig")
         << QString("addressbook_cpp.qbs")
-        << QStringList({"project.qbsModuleProviders:qbspkgconfig", "--no-fallback-module-provider"})
-        << true
-        << true;
+        << QStringList({"project.qbsModuleProviders:qbspkgconfig"}) << true << true;
     QTest::newRow("objc") << QString("addressbook_objc.qbs") << QStringList() << false << true;
     QTest::newRow("nanopb") << QString("addressbook_nanopb.qbs") << QStringList() << false << true;
     QTest::newRow("import") << QString("import.qbs") << QStringList() << true << true;
@@ -8632,10 +8629,7 @@ void TestBlackbox::grpc_data()
     QTest::addColumn<QStringList>("arguments");
     QTest::addColumn<bool>("hasModules");
 
-    QTest::newRow("cpp-fallback") << QString("grpc_cpp.qbs") << QStringList() << true;
-
-    QStringList pkgConfigArgs({
-        "project.qbsModuleProviders:qbspkgconfig", "--no-fallback-module-provider"});
+    QStringList pkgConfigArgs({"project.qbsModuleProviders:qbspkgconfig"});
     // on macOS, openSSL is hidden from pkg-config by default
     if (qbs::Internal::HostOsInfo::isMacosHost()) {
         pkgConfigArgs
diff --git a/tests/auto/blackbox/tst_blackboxproviders.cpp b/tests/auto/blackbox/tst_blackboxproviders.cpp
index 3642ded03..3d64d32d5 100644
--- a/tests/auto/blackbox/tst_blackboxproviders.cpp
+++ b/tests/auto/blackbox/tst_blackboxproviders.cpp
@@ -87,60 +87,6 @@ void TestBlackboxProviders::brokenProvider()
     QCOMPARE(m_qbsStderr.count("This provider is broken"), 2);
 }
 
-void TestBlackboxProviders::fallbackModuleProvider_data()
-{
-    QTest::addColumn<bool>("fallbacksEnabledGlobally");
-    QTest::addColumn<bool>("fallbacksEnabledInProduct");
-    QTest::addColumn<QStringList>("pkgConfigLibDirs");
-    QTest::addColumn<bool>("successExpected");
-    QTest::newRow("without custom lib dir, fallbacks disabled globally and in product")
-            << false << false << QStringList() << false;
-    QTest::newRow("without custom lib dir, fallbacks disabled globally, enabled in product")
-            << false << true << QStringList() << false;
-    QTest::newRow("without custom lib dir, fallbacks enabled globally, disabled in product")
-            << true << false << QStringList() << false;
-    QTest::newRow("without custom lib dir, fallbacks enabled globally and in product")
-            << true << true << QStringList() << false;
-    QTest::newRow("with custom lib dir, fallbacks disabled globally and in product")
-            << false << false << QStringList(testDataDir + "/fallback-module-provider/libdir")
-            << false;
-    QTest::newRow("with custom lib dir, fallbacks disabled globally, enabled in product")
-            << false << true << QStringList(testDataDir + "/fallback-module-provider/libdir")
-            << false;
-    QTest::newRow("with custom lib dir, fallbacks enabled globally, disabled in product")
-            << true << false << QStringList(testDataDir + "/fallback-module-provider/libdir")
-            << false;
-    QTest::newRow("with custom lib dir, fallbacks enabled globally and in product")
-            << true << true << QStringList(testDataDir + "/fallback-module-provider/libdir")
-            << true;
-}
-
-void TestBlackboxProviders::fallbackModuleProvider()
-{
-    QFETCH(bool, fallbacksEnabledInProduct);
-    QFETCH(bool, fallbacksEnabledGlobally);
-    QFETCH(QStringList, pkgConfigLibDirs);
-    QFETCH(bool, successExpected);
-
-    QDir::setCurrent(testDataDir + "/fallback-module-provider");
-    static const auto b2s = [](bool b) { return QString(b ? "true" : "false"); };
-    QbsRunParameters resolveParams("resolve",
-        QStringList{"modules.pkgconfig.libDirs:" + pkgConfigLibDirs.join(','),
-                    "products.p.fallbacksEnabled:" + b2s(fallbacksEnabledInProduct),
-                    "--force-probe-execution"});
-    if (!fallbacksEnabledGlobally)
-        resolveParams.arguments << "--no-fallback-module-provider";
-    QCOMPARE(runQbs(resolveParams), 0);
-    const bool pkgConfigPresent = m_qbsStdout.contains("pkg-config present: true");
-    const bool pkgConfigNotPresent = m_qbsStdout.contains("pkg-config present: false");
-    QVERIFY(pkgConfigPresent != pkgConfigNotPresent);
-    if (pkgConfigNotPresent)
-        successExpected = false;
-    QbsRunParameters buildParams;
-    buildParams.expectFailure = !successExpected;
-    QCOMPARE(runQbs(buildParams) == 0, successExpected);
-}
-
 void TestBlackboxProviders::moduleProviders()
 {
     QDir::setCurrent(testDataDir + "/module-providers");
diff --git a/tests/auto/blackbox/tst_blackboxproviders.h b/tests/auto/blackbox/tst_blackboxproviders.h
index e8477de51..dd0039013 100644
--- a/tests/auto/blackbox/tst_blackboxproviders.h
+++ b/tests/auto/blackbox/tst_blackboxproviders.h
@@ -44,8 +44,6 @@ private slots:
     void allowedValues();
     void allowedValues_data();
     void brokenProvider();
-    void fallbackModuleProvider_data();
-    void fallbackModuleProvider();
     void moduleProviders();
     void moduleProvidersCache();
     void nonEagerModuleProvider();