It seems pretty cryptic, and not due to external configuration errors for instance. External library conflicts, maybe, but if that's the case I'd appreciate insights as to how to tackle them. Here's the backtrace and exact error. Full output from the emacs buffer for the err, in fact. Thank you. p.s. Posting here since I'm not able to detect a user-related mailing list nor a bug tracker. I hope you got some appreciation for users! --- erred while invoking #<COMPILE-OP NIL {AA11E19}> on #<CL-SOURCE-FILE "package" {B2CAA31}> [Condition of type ASDF:COMPILE-FAILED] Restarts: 0: [TRY-RECOMPILING] Try recompiling package 1: [RETRY] Retry performing #<ASDF:COMPILE-OP NIL {AA11E19}> on #<ASDF:CL-SOURCE-FILE "package" {B2CAA31}>. 2: [ACCEPT] Continue, treating #<ASDF:COMPILE-OP NIL {AA11E19}> on #<ASDF:CL-SOURCE-FILE "package" {B2CAA31}> as having been successful. 3: [ABORT] Exit debugger, returning to top level. Backtrace: 0: ((SB-PCL::FAST-METHOD ASDF:PERFORM (ASDF:COMPILE-OP ASDF:CL-SOURCE-FILE)) #<unavailable argument> #<unavailable argument> #<ASDF:COMPILE-OP NIL {AA11E19}> #<ASDF:CL-SOURCE-FILE "package" {B2CAA31}>) 1: ((LAMBDA (SB-PCL::.PV. SB-PCL::.NEXT-METHOD-CALL. SB-PCL::.ARG0. SB-PCL::.ARG1.)) ..) 2: ((SB-PCL::FAST-METHOD ASDF:PERFORM :AROUND (ASDF:COMPILE-OP ASDF:CL-SOURCE-FILE)) ..) 3: ((LAMBDA ())) 4: ((FLET SB-THREAD::WITH-RECURSIVE-LOCK-THUNK)) 5: ((FLET #:WITHOUT-INTERRUPTS-BODY-[CALL-WITH-RECURSIVE-LOCK]508)) 6: (SB-THREAD::CALL-WITH-RECURSIVE-LOCK ..) 7: (SB-C::%WITH-COMPILATION-UNIT #<CLOSURE (LAMBDA #) {ACD4825}>)[:EXTERNAL] 8: (ASDF:OPERATE ASDF:LOAD-OP :CFFI-GROVEL)[:EXTERNAL] 9: (SB-INT:SIMPLE-EVAL-IN-LEXENV (ASDF:OOS 'ASDF:LOAD-OP :CFFI-GROVEL) #<NULL-LEXENV>) 10: (SB-INT:SIMPLE-EVAL-IN-LEXENV (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE) (ASDF:OOS 'ASDF:LOAD-OP :CFFI-GROVEL)) #<NULL-LEXENV>) 11: (SB-FASL::LOAD-AS-SOURCE #<SB-SYS:FD-STREAM for "file /home/hylje/.sbcl/systems/net.sockets.asd" {AA4EEE9}> NIL NIL) 12: ((FLET SB-FASL::LOAD-STREAM) #<SB-SYS:FD-STREAM for "file /home/hylje/.sbcl/systems/net.sockets.asd" {AA4EEE9}>) 13: (LOAD #P"/home/hylje/.sbcl/systems/net.sockets.asd")[:EXTERNAL] 14: (ASDF:FIND-SYSTEM "net.sockets" NIL) 15: ((SB-PCL::FAST-METHOD ASDF:FIND-COMPONENT ((EQL NIL) T)) #<unused argument> #<unused argument> #<unused argument> "net.sockets" NIL) 16: ((LABELS ASDF::DO-ONE-DEP) ASDF:COMPILE-OP :NET.SOCKETS NIL) 17: ((LABELS ASDF::DO-DEP) ASDF:COMPILE-OP (:NET.SOCKETS :IO.STREAMS :IO.MULTIPLEX :IOLIB.BASE)) 18: ((SB-PCL::FAST-METHOD ASDF::TRAVERSE (ASDF:OPERATION ASDF:COMPONENT)) #(3 NIL) #<unavailable argument> #<ASDF:COMPILE-OP NIL {AA468C9}> #<ASDF:SYSTEM "iolib" {AED4C11}>) 19: ((LABELS ASDF::DO-DEP) ASDF:COMPILE-OP ("iolib")) 20: ((SB-PCL::FAST-METHOD ASDF::TRAVERSE (ASDF:OPERATION ASDF:COMPONENT)) #(3 NIL) #<unavailable argument> #<ASDF:LOAD-OP NIL {AA3CDB1}> #<ASDF:SYSTEM "iolib" {AED4C11}>) 21: (ASDF:OPERATE ASDF:LOAD-OP IOLIB)[:EXTERNAL] 22: (SB-INT:SIMPLE-EVAL-IN-LEXENV (ASDF:OOS 'ASDF:LOAD-OP 'IOLIB) #<NULL-LEXENV>) 23: (INTERACTIVE-EVAL (ASDF:OOS 'ASDF:LOAD-OP 'IOLIB)) 24: (SB-IMPL::REPL-FUN NIL) 25: (SB-IMPL::REPL-FUN NIL)[:EXTERNAL] 26: ((LAMBDA ())) 27: ((LAMBDA ()))[:EXTERNAL] 28: (SB-IMPL::%WITH-REBOUND-IO-SYNTAX #<CLOSURE (LAMBDA #) {A83B0B5}>) 29: (SB-IMPL::TOPLEVEL-REPL NIL) 30: (SB-IMPL::TOPLEVEL-INIT) 31: ((LABELS SB-IMPL::RESTART-LISP))