<p dir="auto">I have come across a reproducible segfault in Julia v0.5.0.  I'm afraid it's not very minimal, but it's easy to reproduce.  To reproduce:</p>
<ul dir="auto">
<li>Install branch <code class="notranslate">fsm_matrix_segfault</code> of the package jeff-regier/Celeste.jl (commit 21974)</li>
<li>Check out branch <code class="notranslate">segfault</code> from the repo rgiordan/CelesteDev.jl</li>
<li>Run the Celeste tests with the command <code class="notranslate">test/runtests misc</code> (this will download the data files needed for the test case)</li>
<li>Run the script <code class="notranslate">rasterized_psf/psf_free_image.jl</code> from the CelesteDev.jl directory</li>
</ul>
<p dir="auto">Please let me know if I can provide any more information.  The backtrace is below:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="julia&gt; PSFConvolution.convolve_fsm_images!(fsm_vec[b]);

signal (11): Segmentation fault
while loading no file, in expression starting on line 0
ml_matches_visitor at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:2172
jl_typemap_intersection_node_visitor at /home/rgiordan/Documents/git_repos/julia5/src/typemap.c:496
ml_matches at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:2279 [inlined]
jl_matching_methods at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:2300
methods_including_ambiguous at ./reflection.jl:283
unknown function (ip: 0x7f24d5fbfcc6)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
showerror at ./replutil.jl:277
#showerror#899 at ./replutil.jl:200
unknown function (ip: 0x7f24d5fbc849)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
#5 at ./REPL.jl:119
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
with_output_color at ./util.jl:299
display_error at ./REPL.jl:112
unknown function (ip: 0x7f24d5fbb2fd)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
print_response at ./REPL.jl:147
unknown function (ip: 0x7f24d5fbb14d)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
print_response at ./REPL.jl:139
unknown function (ip: 0x7f24d5fbaf1d)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
#22 at ./REPL.jl:652
unknown function (ip: 0x7f24e5336201)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
#38 at ./REPL.jl:867
#13 at ./LineEdit.jl:736
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
prompt! at ./LineEdit.jl:1605
run_interface at ./LineEdit.jl:1574
unknown function (ip: 0x7f26fea486df)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
run_frontend at ./REPL.jl:903
run_repl at ./REPL.jl:188
unknown function (ip: 0x7f24e532f522)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
_start at ./client.jl:360
unknown function (ip: 0x7f26fea63a78)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
unknown function (ip: 0x40184c)
unknown function (ip: 0x4012e6)
__libc_start_main at /build/glibc-GKVZIf/glibc-2.23/csu/../csu/libc-start.c:291
unknown function (ip: 0x401338)
Allocations: 30470709 (Pool: 30468304; Big: 2405); GC: 45
Segmentation fault (core dumped)"><pre class="notranslate"><code class="notranslate">julia&gt; PSFConvolution.convolve_fsm_images!(fsm_vec[b]);

signal (11): Segmentation fault
while loading no file, in expression starting on line 0
ml_matches_visitor at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:2172
jl_typemap_intersection_node_visitor at /home/rgiordan/Documents/git_repos/julia5/src/typemap.c:496
ml_matches at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:2279 [inlined]
jl_matching_methods at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:2300
methods_including_ambiguous at ./reflection.jl:283
unknown function (ip: 0x7f24d5fbfcc6)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
showerror at ./replutil.jl:277
#showerror#899 at ./replutil.jl:200
unknown function (ip: 0x7f24d5fbc849)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
#5 at ./REPL.jl:119
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
with_output_color at ./util.jl:299
display_error at ./REPL.jl:112
unknown function (ip: 0x7f24d5fbb2fd)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
print_response at ./REPL.jl:147
unknown function (ip: 0x7f24d5fbb14d)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
print_response at ./REPL.jl:139
unknown function (ip: 0x7f24d5fbaf1d)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
#22 at ./REPL.jl:652
unknown function (ip: 0x7f24e5336201)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
#38 at ./REPL.jl:867
#13 at ./LineEdit.jl:736
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
prompt! at ./LineEdit.jl:1605
run_interface at ./LineEdit.jl:1574
unknown function (ip: 0x7f26fea486df)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
run_frontend at ./REPL.jl:903
run_repl at ./REPL.jl:188
unknown function (ip: 0x7f24e532f522)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
_start at ./client.jl:360
unknown function (ip: 0x7f26fea63a78)
jl_call_method_internal at /home/rgiordan/Documents/git_repos/julia5/src/julia_internal.h:189 [inlined]
jl_apply_generic at /home/rgiordan/Documents/git_repos/julia5/src/gf.c:1942
unknown function (ip: 0x40184c)
unknown function (ip: 0x4012e6)
__libc_start_main at /build/glibc-GKVZIf/glibc-2.23/csu/../csu/libc-start.c:291
unknown function (ip: 0x401338)
Allocations: 30470709 (Pool: 30468304; Big: 2405); GC: 45
Segmentation fault (core dumped)
</code></pre></div>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="julia&gt; function foo{T}()
           nothing
       end
WARNING: static parameter T does not occur in signature for foo at REPL[1]:2.
The method will not be callable.
foo (generic function with 1 method)

julia&gt; foo()

signal (11): Segmentation fault: 11
while loading no file, in expression starting on line 0
jl_svecref at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia.h:690 [inlined]
ml_matches_visitor at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:2172
jl_typemap_intersection_node_visitor at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/typemap.c:510 [inlined]
jl_typemap_intersection_visitor at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/typemap.c:570
ml_matches at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:2279 [inlined]
jl_matching_methods at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:2300
methods_including_ambiguous at ./reflection.jl:283
unknown function (ip: 0x11968fc56)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
showerror at ./replutil.jl:277
#showerror#899 at ./replutil.jl:200
unknown function (ip: 0x11968c679)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
#5 at ./REPL.jl:119
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
with_output_color at ./util.jl:299
display_error at ./REPL.jl:112
unknown function (ip: 0x11968ae6d)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
print_response at ./REPL.jl:147
unknown function (ip: 0x11968ac5d)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
print_response at ./REPL.jl:139
unknown function (ip: 0x11968a9ad)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
#22 at ./REPL.jl:652
unknown function (ip: 0x119679a91)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
run_interface at ./LineEdit.jl:1579
jlcall_run_interface_20650 at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
run_frontend at ./REPL.jl:903
run_repl at ./REPL.jl:188
unknown function (ip: 0x1196765e2)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
_start at ./client.jl:360
jlcall__start_21452 at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
true_main at /Applications/Julia-0.5.app/Contents/Resources/julia/bin/julia (unknown line)
main at /Applications/Julia-0.5.app/Contents/Resources/julia/bin/julia (unknown line)
Allocations: 3028631 (Pool: 3027665; Big: 966); GC: 2

[Process completed]"><pre class="notranslate"><code class="notranslate">julia&gt; function foo{T}()
           nothing
       end
WARNING: static parameter T does not occur in signature for foo at REPL[1]:2.
The method will not be callable.
foo (generic function with 1 method)

julia&gt; foo()

signal (11): Segmentation fault: 11
while loading no file, in expression starting on line 0
jl_svecref at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia.h:690 [inlined]
ml_matches_visitor at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:2172
jl_typemap_intersection_node_visitor at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/typemap.c:510 [inlined]
jl_typemap_intersection_visitor at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/typemap.c:570
ml_matches at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:2279 [inlined]
jl_matching_methods at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:2300
methods_including_ambiguous at ./reflection.jl:283
unknown function (ip: 0x11968fc56)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
showerror at ./replutil.jl:277
#showerror#899 at ./replutil.jl:200
unknown function (ip: 0x11968c679)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
#5 at ./REPL.jl:119
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
with_output_color at ./util.jl:299
display_error at ./REPL.jl:112
unknown function (ip: 0x11968ae6d)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
print_response at ./REPL.jl:147
unknown function (ip: 0x11968ac5d)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
print_response at ./REPL.jl:139
unknown function (ip: 0x11968a9ad)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
#22 at ./REPL.jl:652
unknown function (ip: 0x119679a91)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
run_interface at ./LineEdit.jl:1579
jlcall_run_interface_20650 at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
run_frontend at ./REPL.jl:903
run_repl at ./REPL.jl:188
unknown function (ip: 0x1196765e2)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
_start at ./client.jl:360
jlcall__start_21452 at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:189 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1942
true_main at /Applications/Julia-0.5.app/Contents/Resources/julia/bin/julia (unknown line)
main at /Applications/Julia-0.5.app/Contents/Resources/julia/bin/julia (unknown line)
Allocations: 3028631 (Pool: 3027665; Big: 966); GC: 2

[Process completed]
</code></pre></div>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="julia&gt; versioninfo()
Julia Version 0.5.0
Commit 3c9d753 (2016-09-19 18:14 UTC)
Platform Info:
  System: Darwin (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.7.1 (ORCJIT, broadwell)"><pre class="notranslate"><code class="notranslate">julia&gt; versioninfo()
Julia Version 0.5.0
Commit 3c9d753 (2016-09-19 18:14 UTC)
Platform Info:
  System: Darwin (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.7.1 (ORCJIT, broadwell)
</code></pre></div>