Creating static archives with ar or libtool fails on jailbroken iOS - ios

Question

I'm trying to build and run Go on a self-hosted jailbroken iOS device (Corellium virtual devices). Go bootstraps and can build and run regular binaries. However, Go archives fail to build because ar doesn't work:
$ dpkg -S /usr/bin/clang /usr/bin/ar /usr/bin/libtool
org.coolstar.llvm-clang64: /usr/bin/clang
org.coolstar.cctools: /usr/bin/ar
org.coolstar.cctools: /usr/bin/libtool
$ apt policy org.coolstar.cctools org.coolstar.llvm-clang64
org.coolstar.cctools:
Installed: 895
Candidate: 895
Version table:
*** 895 500
500 http://apt.thebigboss.org/repofiles/cydia stable/main iphoneos-arm Packages
100 /Library/dpkg/status
org.coolstar.llvm-clang64:
Installed: 5.0.1-2
Candidate: 5.0.1-2
Version table:
*** 5.0.1-2 500
500 http://apt.thebigboss.org/repofiles/cydia stable/main iphoneos-arm Packages
100 /Library/dpkg/status
$ ../bin/go build -buildmode=c-archive -ldflags="-v" -work ../misc/ios/detect.go
WORK=/tmp/go-build734936238
# command-line-arguments
HEADER = -H1 -T0x2000 -R0x1000
0.00 deadcode
0.05 symsize = 0
0.08 pclntab=740717 bytes, funcdata total 185492 bytes
0.08 dodata
0.08 symsize = 0
0.08 symsize = 0
0.09 dynreloc
0.09 dwarf
0.12 asmb
0.13 datblk
0.14 reloc
0.20 sym
0.22 header
archive: ar -q -c -s $WORK/b001/exe/a.out.a /tmp/go-link-569975294/go.o /tmp/go-link-569975294/000000.o /tmp/go-link-569975294/000001.o /tmp/go-link-569975294/000002.o /tmp/go-link-569975294/000003.o /tmp/go-link-569975294/000004.o /tmp/go-link-569975294/000005.o /tmp/go-link-569975294/000006.o /tmp/go-link-569975294/000007.o /tmp/go-link-569975294/000008.o /tmp/go-link-569975294/000009.o /tmp/go-link-569975294/000010.o /tmp/go-link-569975294/000011.o /tmp/go-link-569975294/000012.o /tmp/go-link-569975294/000013.o /tmp/go-link-569975294/000014.o
/var/mobile/go-tip/pkg/tool/darwin_arm64/link: running ar failed: exit status 1
fatal error: ar: can't find or exec: /usr/bin/arm64-apple-darwin14-ranlib (No such file or directory)
ar: internal ranlib command failed
Optimistic as I am, I tried symlinking ranlib:
# ln -s /usr/bin/ranlib /usr/bin/arm64-apple-darwin14-ranlib
$ ../bin/go build -buildmode=c-archive -ldflags="-v" -work ../misc/ios/detect.go
WORK=/tmp/go-build239621581
# command-line-arguments
HEADER = -H1 -T0x2000 -R0x1000
0.00 deadcode
0.06 symsize = 0
0.08 pclntab=740717 bytes, funcdata total 185492 bytes
0.08 dodata
0.09 symsize = 0
0.09 symsize = 0
0.09 dynreloc
0.10 dwarf
0.12 asmb
0.13 datblk
0.15 reloc
0.20 sym
0.22 header
archive: ar -q -c -s $WORK/b001/exe/a.out.a /tmp/go-link-618780113/go.o /tmp/go-link-618780113/000000.o /tmp/go-link-618780113/000001.o /tmp/go-link-618780113/000002.o /tmp/go-link-618780113/000003.o /tmp/go-link-618780113/000004.o /tmp/go-link-618780113/000005.o /tmp/go-link-618780113/000006.o /tmp/go-link-618780113/000007.o /tmp/go-link-618780113/000008.o /tmp/go-link-618780113/000009.o /tmp/go-link-618780113/000010.o /tmp/go-link-618780113/000011.o /tmp/go-link-618780113/000012.o /tmp/go-link-618780113/000013.o /tmp/go-link-618780113/000014.o
/var/mobile/go-tip/pkg/tool/darwin_arm64/link: running ar failed: exit status 1
/usr/bin/arm64-apple-darwin14-ranlib: archive member: $WORK/b001/exe/a.out.a(go.o) offset in archive not a multiple of 8 (must be since member is an 64-bit object file)
fatal error: ar: fatal error in /usr/bin/arm64-apple-darwin14-ranlib
I even switched Go to use libtool:
$ ../bin/go build -buildmode=c-archive -ldflags="-v" -work ../misc/ios/detect.go
WORK=/tmp/go-build502332895
# command-line-arguments
HEADER = -H1 -T0x2000 -R0x1000
0.00 deadcode
0.04 symsize = 0
0.08 pclntab=740717 bytes, funcdata total 185492 bytes
0.08 dodata
0.08 symsize = 0
0.09 symsize = 0
0.09 dynreloc
0.10 dwarf
0.12 asmb
0.14 datblk
0.15 reloc
0.20 sym
0.22 header
archive: libtool -static -o $WORK/b001/exe/a.out.a /tmp/go-link-320669019/go.o /tmp/go-link-320669019/000000.o /tmp/go-link-320669019/000001.o /tmp/go-link-320669019/000002.o /tmp/go-link-320669019/000003.o /tmp/go-link-320669019/000004.o /tmp/go-link-320669019/000005.o /tmp/go-link-320669019/000006.o /tmp/go-link-320669019/000007.o /tmp/go-link-320669019/000008.o /tmp/go-link-320669019/000009.o /tmp/go-link-320669019/000010.o /tmp/go-link-320669019/000011.o /tmp/go-link-320669019/000012.o /tmp/go-link-320669019/000013.o /tmp/go-link-320669019/000014.o
/var/mobile/go-tip/pkg/tool/darwin_arm64/link: running libtool failed: signal: segmentation fault
Now, ar (with symlinked ranlib) fails on even simple object files:
$ cat blah.c
int blah() {
return 0;
}
$ clang -c blah.c
$ ar -q -c -s blah.a blah.o
/usr/bin/arm64-apple-darwin14-ranlib: archive member: blah.a(blah.o) offset in archive not a multiple of 8 (must be since member is an 64-bit object file)
Libtool works:
$ libtool -static -o blah.a blah.o
But segfaults on more complex object files as seen above.
Go can already successfully create archives using the Xcode ar tool. It's only the iOS native "cctools" version that fails.

Answer 1

I worked around the problem by using llvm-ar. The command line flags are slightly different, but at least I now have a working archive.