Building swig on core-updates, I saw this result:

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BEGIN failed--compilation aborted at runme.pl line 3.
make[3]: *** [../../Makefile:285: perl5_run] Error 2                                                               
make[2]: *** [Makefile:10: check] Error 2                                                        
make[1]: *** [Makefile:252: variables.actionexample] Error 2
make: *** [Makefile:237: check-perl5-examples] Error 2                                                                                                              
make: *** Waiting for unfinished jobs....                            
starting swig testsuite hardlink
starting testsuite cpp2                                                                                                                                                                         starting swig testsuite cpp2                                                                                                                                                                    starting testsuite nlevels4                                                                                                                                                                     starting testsuite nlevels1                                                                                                                                              
test done - OK                                       
make[1]: Leaving directory '/tmp/guix-build-swig-3.0.10.drv-0/swig-3.0.10/CCache'
phase `check' failed after 120675000.0 seconds
builder for `/gnu/store/zyak5xkiqw2y9b6pqb73x2ppr5sj8phg-swig-3.0.10.drv' failed with exit code 1
@ build-failed /gnu/store/zyak5xkiqw2y9b6pqb73x2ppr5sj8phg-swig-3.0.10.drv - 1 builder for `/gnu/store/zyak5xkiqw2y9b6pqb73x2ppr5sj8phg-swig-3.0.10.drv' failed with exit code 1
guix build: error: build failed: build of `/gnu/store/zyak5xkiqw2y9b6pqb73x2ppr5sj8phg-swig-3.0.10.drv' failed  
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Note that the check phase failed after 120675000.0 seconds. I know it
didn't take 3.8 years.