454 -> sudo port rev-upgrade
--->  Scanning binaries for linking errors
--->  No broken files found.
--->  Found 1 broken port, determining rebuild order
You can always run 'port rev-upgrade' again to fix errors.
The following ports will be rebuilt: pdftk @2.02+gcc5
Continue? [Y/n]: Y
--->  Computing dependencies for pdftk
--->  Cleaning pdftk
--->  Scanning binaries for linking errors
--->  No broken files found.
--->  Found 1 broken port, determining rebuild order
--->  Rebuilding in order
     pdftk @2.02 +gcc5
--->  Computing dependencies for pdftk
--->  Fetching distfiles for pdftk
--->  Verifying checksums for pdftk
--->  Extracting pdftk
--->  Applying patches to pdftk
--->  Configuring pdftk
--->  Building pdftk
--->  Staging pdftk into destroot
--->  Deactivating pdftk @2.02_0+gcc5
--->  Cleaning pdftk
--->  Uninstalling pdftk @2.02_0+gcc5
--->  Cleaning pdftk
--->  Computing dependencies for pdftk
--->  Installing pdftk @2.02_0+gcc5
--->  Activating pdftk @2.02_0+gcc5
--->  Cleaning pdftk
--->  Scanning binaries for linking errors
--->  No broken files found.                             
--->  Found 1 broken port, determining rebuild order
--->  Rebuilding in order
     pdftk @2.02 +gcc5
--->  Computing dependencies for pdftk
--->  Fetching distfiles for pdftk
--->  Verifying checksums for pdftk
--->  Extracting pdftk
--->  Applying patches to pdftk
--->  Configuring pdftk
--->  Building pdftk
--->  Staging pdftk into destroot
--->  Deactivating pdftk @2.02_0+gcc5
--->  Cleaning pdftk
--->  Uninstalling pdftk @2.02_0+gcc5
--->  Cleaning pdftk
--->  Computing dependencies for pdftk
--->  Installing pdftk @2.02_0+gcc5
--->  Activating pdftk @2.02_0+gcc5
--->  Cleaning pdftk
--->  Scanning binaries for linking errors
--->  No broken files found.
Error: Port pdftk is still broken after rebuilding it more than 3 times.
Error: Please run port -d -y rev-upgrade and use the output to report a bug.
Error: rev-upgrade failed: Port pdftk still broken after rebuilding 3 times
Error: Follow https://guide.macports.org/#project.tickets to report a bug.