Fix bundler 4.x incompatibility caused by rubygems 4.x update by tnikolova82 · Pull Request #1131 · cloudfoundry/ruby-buildpack

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 · 2026-04-06T11:00:02Z

Summary

This PR fixes two issues blocking the CF integration tests with cflinuxfs4 + cflinuxfs5:

1. Bundler 4.x incompatibility (Bug 5)

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs
ruby setup.rb, it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.7.2.

Changes:

src/ruby/versions/ruby.go — Updated GetBundlerVersion() regex to handle both
Bundler version X.Y.Z (bundler 2.x) and X.Y.Z (date hash) (bundler 4.x) formats
supply/supply.goUpdateRubygems() — Re-install bundler 2.x after rubygems update
when rubygems major version >= 4
supply/supply.goInstallBundler() — Fixed version selection: bundler 1.x uses
"1.x.x" dependency, everything else uses "2.x.x"
supply/supply.goVendorBundlePath() — Only bundler 1.x uses nested vendor path
supply/supply.goInstallGems() — Bundler removal applies to bundler 2+
Added tests for bundler 2.x BUNDLED WITH, bundler 4.x vendor_bundle, and
rubygems 4.x re-install scenarios

2. Switchblade multi-stack buildpack deletion (Bug 8)

When CF has both cflinuxfs4 and cflinuxfs5 stacks deployed, multiple buildpacks share
the same name (e.g., ruby_buildpack for each stack). The switchblade Initialize()
method called cf delete-buildpack -f <name> without -s <stack>, which fails with:

Multiple buildpacks named ruby_buildpack found. Specify a stack name by using a '-s' flag.

Changes:

vendor/.../switchblade/internal/cloudfoundry/initialize.go — Parse stack field
from /v3/buildpacks API response and iterate over all resources, deleting each
with the appropriate -s <stack> flag. Handles null-stack buildpacks by omitting
the -s flag when stack is empty.

This is a vendored fix; the upstream switchblade repo (v0.9.4) has the same bug.

Rubygems 4.0.9 ships bundler 4.x as a default gem. When UpdateRubygems() runs 'ruby setup.rb', it installs bundler 4.0.9 which overwrites the buildpack's bundler 2.x. Bundler 4.x changed 'bundle version' output format (omits 'Bundler version' prefix), breaking GetBundlerVersion(). Changes: - GetBundlerVersion() regex: handle both bundler 2.x and 4.x output formats - UpdateRubygems(): re-install manifest bundler after 'ruby setup.rb' - InstallBundler(): invert version selection to default to 2.x.x - VendorBundlePath(): only bundler 1.x uses nested path (future-proof) - InstallGems(): only bundler 1.x skips BUNDLED WITH removal (future-proof) - Tests: add bundler 2.x/4.x test cases, update UpdateRubygems test

The unconditional re-install caused the integration cache test to fail: on first deploy, the second InstallBundler() call (from UpdateRubygems) produced a 'Copy' line since libbuildpack had already cached the tarball from the initial Download, violating the cache test assertion that no Copy lines appear on first deploy. Fix: only re-install bundler when rubygems major version >= 4, since only rubygems 4.x ships bundler 4.x as a default gem. Rubygems 3.x ships bundler 2.x which doesn't overwrite the buildpack's bundler.

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility caused by rubygems 4.x update~~Fix bundler 4.x incompatibility and switchblade multi-stack deletionApr 9, 2026

tnikolova82 mentioned this pull request Apr 9, 2026
Fix switchblade Initialize() multi-stack buildpack deletion #1136
Closed

tnikolova82 added 2 commits April 15, 2026 10:10

tnikolova82 force-pushed the fix-bundler-4x-compatibility branch from 1576f01 to 39cbad9Compare April 15, 2026 07:11

tnikolova82 changed the title ~~Fix bundler 4.x incompatibility and switchblade multi-stack deletion~~Fix bundler 4.x incompatibility caused by rubygems 4.x updateApr 15, 2026

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tnikolova82 commented Apr 6, 2026• edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

1. Bundler 4.x incompatibility (Bug 5)

2. Switchblade multi-stack buildpack deletion (Bug 8)

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tnikolova82 commented Apr 6, 2026• edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

1. Bundler 4.x incompatibility (Bug 5)

2. Switchblade multi-stack buildpack deletion (Bug 8)

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tnikolova82 commented Apr 6, 2026• edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

1. Bundler 4.x incompatibility (Bug 5)

2. Switchblade multi-stack buildpack deletion (Bug 8)

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tnikolova82 commented Apr 6, 2026• edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

1. Bundler 4.x incompatibility (Bug 5)

2. Switchblade multi-stack buildpack deletion (Bug 8)

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tnikolova82 commented Apr 6, 2026• edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

1. Bundler 4.x incompatibility (Bug 5)

2. Switchblade multi-stack buildpack deletion (Bug 8)

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tnikolova82 commented Apr 6, 2026•
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