<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> No, you will need to build MPICH yourself, stand-alone and then direct PETSc's configure to use what you have built.<div><br></div><div> Barry</div><div><br><div><br><blockquote type="cite"><div>On Jul 21, 2023, at 11:11 AM, Robert Crockett via petsc-users <petsc-users@mcs.anl.gov> wrote:</div><br class="Apple-interchange-newline"><div><meta charset="UTF-8"><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 18px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Hello,<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">I built PETSc with –with-cxx=0 in order to get around a likely Intel C++ compiler bug.<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">However, the MPICH that also gets built by PETSc then picks up the wrong C++ compiler; mpicxx -show indicates that it is using G++, while mpicc is correctly using icc.<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Is there a way to get PETSc to pass the correct C++ compiler for the MPICH build when using –with-cxx=0? I need to compile parts of my own program with mpicxx/icpc.<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif; line-height: 16.866667px;"><span style="font-size: 12.5pt; line-height: 19.166666px; font-family: Georgia, serif;">Robert Crockett</span><span style="font-size: 16pt; line-height: 24.533335px; font-family: Georgia, serif;"><span class="Apple-converted-space"> </span><br></span><span style="font-size: 9pt; line-height: 13.8px; font-family: Georgia, serif;">Plasma Simulation Engineer | OCTO - Computational Products</span><span style="font-size: 16pt; line-height: 24.533335px; font-family: Georgia, serif;"><br></span><span style="font-size: 9pt; line-height: 13.8px; font-family: Arial, sans-serif;">P:<span class="Apple-converted-space"> </span></span><span style="font-size: 9pt; line-height: 13.8px; font-family: Arial, sans-serif; color: rgb(68, 68, 68);">617.648.8349</span><span style="font-size: 9pt; line-height: 13.8px; font-family: Arial, sans-serif;"> M: 415.205.4567</span><span style="font-size: 9pt; line-height: 13.8px; font-family: Arial, sans-serif;"><br><br></span><b><span style="font-size: 7pt; line-height: 10.733333px; font-family: Arial, sans-serif;">LAM RESEARCH<br></span></b><span style="font-size: 7pt; line-height: 10.733333px; font-family: Arial, sans-serif;">4650 Cushing Pkwy, Fremont CA 94538 USA<span class="Apple-converted-space"> </span><br></span><a href="https://www.lamresearch.com/"><span style="font-size: 7pt; line-height: 10.733333px; font-family: Arial, sans-serif;">lamresearch.com</span></a><o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif; line-height: 16.866667px;"><span style="font-size: 16pt; line-height: 24.533335px; font-family: Georgia, serif;"><span id="cid:image001.png@01D9BBC4.11B5C6D0"><image001.png></span></span><o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></div></div><div style="caret-color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-size: 8pt; font-family: Arial;"><br>LAM RESEARCH CONFIDENTIALITY NOTICE: This e-mail transmission, and any documents, files, or previous e-mail messages attached to it, (collectively, "E-mail Transmission") may be subject to one or more of the following based on the associated sensitivity level: E-mail Transmission (i) contains confidential information, (ii) is prohibited from distribution outside of Lam, and/or (iii) is intended solely for and restricted to the specified recipient(s). 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