Originally posted by: skyhigh_

Hi everyone:

  I get some problems while trying to install Scipy for Python3.6.6 on Aix6.1, and the error message is as below:

  ld: 0711-317 ERROR: Undefined symbol: .sgemm_

  ld: 0711-317 ERROR: Undefined symbol: .dgemm_

  Case in https://github.com/scipy/scipy/issues/6685 might be the problem i meet with now, because the error output is nearly the same, but the issue still remains open.

  Is there a way to fix it?

  My environment:

    AIX6.1, xlc13, xlf15

  python3.6.6

  lapack3.4.1, blas3.4.1

  Pip list:

    Cython0.28.5

  numpy1.15

  pytz2018.5

  six1.11.0

  python-dateutil2.7.3

Originally posted by: Phani Kumar Ayyagari

You need to build lapack source with 64 bit options. 

--- make.inc    2018-11-16 05:15:26.000000000 -0600
+++ make.inc.example    2017-11-12 22:15:54.000000000 -0600
@@ -19,8 +19,8 @@
  #  and handle these quantities appropriately. As a consequence, one
  #  should not compile LAPACK with flags such as -ffpe-trap=overflow.
  #
- FORTRAN = gfortran -maix64
- OPTS    = -O2 -frecursive
+ FORTRAN = gfortran
+ OPTS    = -O2 -frecursive
  DRVOPTS = $(OPTS)
  NOOPT   = -O0 -frecursive

@@ -28,12 +28,12 @@
  #  load options for your machine.
  #
  LOADER   = gfortran
- LOADOPTS = -maix64
+ LOADOPTS =

  #  The archiver and the flag(s) to use when building an archive
  #  (library).  If your system has no ranlib, set RANLIB = echo.
  #
- ARCH      = ar -X64
+ ARCH      = ar
  ARCHFLAGS = cr
  RANLIB    = ranlib

After changing as shown in the above code, I could solve the error.

In addition to this, you may need to follow steps at